Bedbugs, sketchy people, and more!
I am going out on a limb here, because of my specific situation they will know exactly who I am and will have all of my info. However, nothing in my review is a lie or exaggeration, and I feel the public needs to know about my experience at Mainstay Suites. 
First and foremost, this place has bedbugs. For those of you not in the know, bedbugs cause skin irritation via bites and can be extremely difficult and costly to eradicate. 
My girlfriend and I picked Mainstay Suites to stay because they are an extended stay hotel. This means that you can get a weekly or monthly rate and stay basically as long as you want. Some other reviewers were complaining about this, but this is not necessarily a bad thing. We needed a temporary place because we had just moved to Phoenix and were house hunting. The rooms are equipped with kitchenettes, including a dishwasher, range top, and full size fridge to make the stay more comfortable. 
About a week into our stay my girlfriend started noticing bites on her body and limbs. We suspected bed bugs, but didn’t have any other proof, and couldn’t be sure if it wasn’t from mosquitoes or something like that. Some people do not have reactions to bed bug bites, and I am one of those people. A couple of agonizing weeks went by until we woke up one morning and caught a live bedbug in the bed, we finally had proof. We also caught a nymph after searching the bed and frame. We notified the staff and after much discussion they told us EcoLab was coming to exterminate the bugs. The moved us to another room and asked us to bring only what we absolutely needed so that we don’t carry the bugs with us. Naturally, the first thing we did in the new room was inspect for bedbugs, and we found bedbug sheddings in the bed. We notified them again and they moved us again. In the third room we couldn’t find any indication of bedbugs, and agreed to stay there for that night. In the third room, however, we did find a pack of zigzags (for rolling marijuana joints) under the bed. A pretty good indication of the drug use and sales that occur at this property. We also found blood in the toilet of that room as well, and it was supposedly a clean room.
The first staff member told us that Ecolab would come and use a heat treatment to clean the room the next day. She then handed us a roll of trash bags and told us to bag up all of our clothes to prevent the bugs from getting into them. We had other questions, and tried to contact Ecolab, but they refused to talk to us, we had to go through the hotel staff to contact them. We asked the staff to have the Ecolab tech contact us directly, this never happened, even after asking several times. The arrival time and date of the exterminator was ambiguous and we heard several different days/times from the hotel staff. When the techs arrived, it turns out the staff hired some other pest control company (Naturzone) instead of Ecolab. The staff called me in the middle of the day to let me know the techs were on site, so I had to leave work to come get my questions answered. Upon arrival at the hotel, I discovered the techs had asked the staff to move our belongings out of our room and into an empty room for extermination. So when I got to our room all of my stuff was in the hallway and being hauled away by maintenance staff upstairs. This all happened without notification or approval by us, but I understood that it needed done and helped them move the rest of the stuff upstairs. The techs were also not using heat treatment, but simply a spray can full of pesticide. After they sprayed, we moved all of our belongings back from both rooms into our original room as requested. The techs mentioned that the staff were going to pay to have our bagged clothing cleaned, but this was never communicated to us by the staff and nothing ever came of it. We spent quite a bit of money at the laundromat cleaning all of our clothes to prevent further infestation. The company did install bedbug certified mattress and box spring covers as well.
One of the staff members that we talked to was empathetic about the bedbugs because she said she has them at home. She mentioned that she previously lived in a house with 15 people and had begbugs all the time, and has recently moved to an apartment with 11 people in it and she gets bites all the time. That whole living situation sounds shady enough to me, but to top it off she works at a hotel and knowingly has bedbugs at home. I feel there is a good chance she is inadvertently bringing them in. 
A few days after they sprayed, we noticed more bites. I did eventually find more bedbug fecal spotting in the sheets. We got a view of the laundry room a couple of times, and the clean bedding is right next to the soiled bedding, so there is a chance that the bugs are going from room to room via the bedding. We suspected so, and decided to put the Do Not Disturb sign on our door to prevent housekeeping from changing our bedding. I stopped there during my lunch break and the housekeeper had ignored the sign and gone into the room anyway. She also entered the room on a different day without knocking while I was in there. However, we didn’t have any theft so I think she was just doing her job.
On to the other issues:
To put it simply, there are some very sketchy people staying at mainstay. One of the most common problems was that the side doors were always propped open with rocks or twigs or other items. We would always undo them when we found them. On more than one occasion there would be a random person waiting by the door to get in, and once someone with a card happened to come by they would grab the door and walk in. I understand if someone forgot their key or whatever, but this was happening all the time. It was always different people and most looked really rough. We suspected drug activity, as legitimate guests had keys, or if they were visiting they could at least call the resident and have them come down and open the door. There really aren’t any other explanations for this behavior, they were trying to get in based on the knowledge that they could score drugs from room number X, but didn’t have any contact info other than that. We once exited the side door and two very rough looking women were standing outside the door smoking cigarettes. As soon as we walked away they grabbed the door and started hauling stuff inside. They kept darting their eyes around to see if they were being watched. You could just tell they weren’t supposed to be there, the look on their faces gave them away. 
One group of guests is a guy and his two young kids. I had a few encounters with this group, and I’m still not sure what to think about it. The first encounter happened when we were using the fitness center. As we entered, the two children were playing around on the treadmills. They got the hint and left the room right away. However, they kept coming by the door and yelling “boo!” then running away laughing. I’m not a fan of unsupervised children, and when I’m trying to work out I don’t want any distractions. So I shut the door, and the kids then came back, opened the door and yelled “boo!” again and ran off. Eventually I shut and locked the door so they couldn’t get in. My second encounter was when I saw the same two children, with their father this time. They were waiting outside the side door and pulled the same trick as I described above, when I entered the door the dad jumped for the handle to try to get in. I caught it out of the corner of my eye, but the door shut just before he got there. The next time I saw them was off property of the hotel, they were sitting in the parking lot at Fry’s with a cardboard sign begging for money. I saw them there a couple of other days as well. That’s right, when you give money to these supposedly homeless people, it goes to their hotel bill. My third encounter came after 10pm when someone was knocking on our door. It turned out to be this same guy, and he was just asking if the small dog in the hallway was ours, which it was not. I suppose he was doing the right thing in this case. Later, I was making a quick repair on my vehicle in the parking lot. This guy and the two kids were wandering around the pool area, and he was checking the ashtrays for cigarette butts that he could use. The two kids each had toy guns, and kept sneaking up on me and pretending to shoot me. I am a responsible gun owner, and I do not think its ok to let kids point toy guns at total strangers and pretend to shoot them.
On top of the people acting sketchy, they are DIRTY. There is trash dropped in random places all the time. Every day I noticed a new piece of garbage in the hallway. The staff would eventually clean it up, but the people staying there seemed to just drop whatever trash they had wherever they pleased. The stairwell near our room was especially bad and had a strong urine odor. The light was also out in that stairwell for our entire stay, of almost two months. There is also a lot of door slamming late at night and children running through the hallways.
Some guests on here complained about their rooms being in disrepair. Our room was in generally good shape, however the headboard had a panel that had fallen on the floor. We fixed this ourselves. The other rooms that had us check into were in much worse shape than ours. The TVs are the old CRT type, and we brought in our own flatscreen to use instead. The CRT TVs are mounted on a locked swivel base on the dresser, and you cannot remove it without a key. We asked the staff if they could unlock it and move the TV out so we could put our own on the stand. We were told that it was no problem and that they would do it the next day. A week went by and nothing happened. We asked again, and they said they didn’t have the key, thus couldn’t remove it. We decided to get our clothes out of the dresser and have them remove the whole thing. We could then put our TV on a different piece of furniture for the time being. We removed our clothes and waited…. And waited… and another week went by and it was not even touched. When the bedbug stuff was going on, I asked the maintenance guy if he could unlock the TV as we had requested and move it out. He agreed to and said he would go get the key from the desk (he was sure they actually had it). He never came back and the TV never got moved for our entire stay. It seemed like such a simple request yet they could not fulfill it. 
The hotel is pet friendly. The carpet in the hallways has long tracts where it was torn up by animals. Now we are dog lovers, despite not having any pets, but the shape of the carpeting in the public areas was dismal.
One of the bonuses of this place is that they do have free breakfast from 6am to 9am every day. While I can’t really complain about free food, I didn’t eat it much because I don’t like sweets, and all of their breakfast items were sugar-laden. They had cereal, yogurt, waffles, donuts, etc. I would have really appreciated something savory, like biscuits and gravy or maybe some sausage at some point. 
The pool is often filled with children. If you have kids, the pool is probably great for you. For us, we just wanted a relaxing time which is hard to do with a bunch of screaming kids around. There were also plenty of older kids rough housing in there at random times. One weekend we were awakened by shrieking little girl who was so loud we could hear her through our second floor window, which was closed, and this was before 8:00am. Out of the nearly two months we were at mainstay, we only used the pool area three times. The last time we used it, the water was ice cold, and the hot tub water was barely warm at all.
On the plus side, the front desk staff was always very nice to us and called us by name after checking in. They were sympathetic to our bedbug issue, as most of it was out of their hands they seemed to share our frustration.
So if you can see past the sketchy lowlifes, the shrieking children in the pool, the bedbugs (which can cost people thousands of dollars to remove from their homes), and the myriad of other issues, Mainstay might be the choice for you. The monthly rate was decent at least. I would not put my worst enemies in this hotel.