Noisy from the 17th floor! Not a good choice St. Patty's weekend.
We (my fiance and I) have been wanting to stay at the Marriott Custom House since our first visit to Boston. It's a beautiful historic clock tower, and pricey--which is why we never got to stay until recently. We were surprised to find that the rates at Custom House were actually less than other Marriott's in the city for the weekend of the St. Patty's Parade (we paid about $240 a night for 3/17/2012--3/19/2012).
We stayed in room #1701 on the 17th floor with windows facing Fanuiel Hall and Christopher Columbus park.
POSITIVES:
It's located beside Fanueil Hall and Quincy Market, near the New England Aquarium, North End, and Long Wharf, and it's really a great spot for tourists. It's right beside the Aquarium T-stop.
The main lobby is nicely decorated, and the view up from the second floor rotunda is pretty cool. We arrived pretty late for check-in and the hotel is only accessible with a keycard late at night so we had to buzz to get checked in--the elevators for floors 1-19 require swiping your key card (A second elevator for 19-and up doesn't require a card). A nice safety feature for guests.
The front desk staff woman was friendly. She was very cordial and helpful during check-in.
As for the room, you decent amount for your space. Here the rooms are "suites". They come with a small living room, bedroom (of course), a mini-kitchen that has a mini fridge, microwave, sink, coffee maker, plates, cups, utensils, blender, and toaster.
There were blackout shades throughout the unit.
The mattress on the bed was very comfortable.
The bathroom shower head was adjustable so that you could change the type of spray and whether it was high or low. It also took little to no time at all for the water to heat up.
The 26th floor is an observation deck that encircles the building and you can see the city and harbor from it. There's a couple tables with chairs to sit and enjoy the view. We went up there late at night to look at the city lights one night and then went up to watch the sunset. It's a beautiful view and a nice perk.
The 24th floor is a gameroom with the clock mechanism, there's laundry machines on the backside as well as vending machines and the ice machine.
A 24-hour Tedeschi convenience store is across from the hotel. We went there for some late night food to bring back to the room when it was only fully packed bars open in Fanueil Hall.
NEGATIVES:
Even though we were on the 17th floor, we could still clearly hear the partying going on in the bars on the street below the weekend of St. Patty's... including all the emergency personnel sirens.
I'm a member of Marriott Rewards and for one of their top vacation resorts, not all of my requests were fulfilled--which says a lot because they're expected to meet all your requests and I only asked for 3 things: a city view room, extra towels and extra foam pillows. We got the view and towels, but no extra pillows.
The couch had some weird stains on the sitting edge.
The bathroom was very oddly shaped and I really question how thoroughly it had been cleaned. There were gross drip stains on the outter front edge of the toilet, the grout between the tiles in the shower didn't look clean, and when I opened up a hand towel to dry my face a small LIVE bug fell out--YES, live.
The ice machine was on the 24th floor, the same as the game room. The fridge in the room just doesn't have the capability of producing a bucket worth of ice. And there was no liners provided for the ice bucket. 
There's a very small bar... VERY small bar in the Counting Room on the second floor rotunda. And with that said, we waited for a fairly long time to get our drinks because the bartender thought we were with this other group of people that entered the bar at the same time as us.
Breakfast is also served in the Counting Room, however it's minimal and a help yourself continental style... and you even have to fill out a card documenting what you should be billed for. I would expect a continental style breakfast at this hotel's price to be included.
Our second night there, we went up to the Observation Deck to watch the sun set over the city. We were the only ones up there, and weren't even there for 2 minutes when we were approached by a staff member and told that the general public was not allowed up there. Of course we looked at him with confusion because we had every right to be there--we were paying rental guests of the hotel. He was ready to escort us off the observation deck at 5:15pm when it doesn't close until 11pm. I'm sorry? We were the general public? He demanded that we present proof that we were guests or else we had to leave so I presented our key card and he had the biggest look of shock on his face that we were actually guests. He did apologize but I still feel that the treatment we received was uncalled for. I can't help but think they must not be used to having guests as young as us stay there--as even on the first day there, older guests were asking us in the elevator how we were able to stay there; were we using our parents timeshare or did they have condo (They too, were surprised when we said we were renting).
The complimentary internet was deactivated prior to our checkout time. We were up late and just after midnight (now the wee hours of our checkout day)--it was no longer available for use.
No paper copy of the summary of charges the day of checkout. I'm supposed to just assume I'm getting billed properly without being able to see the bill? That doesn't seem right.
OVERALL:
It was an ok stay, we weren't overly impressed--more disappointed than anything since we had fairly high expectations of the place. The noise was a big issue, as was the rude staff member, and lack of detail to the cleanliness of the bathroom. Perhaps if we stayed on a weekend other than St. Patty's we would have had better luck. Having the mini-kitchen and a room that size was great but we can get that as well as a complimentary breakfast and a cleaner bathroom elsewhere for much cheaper in a location convenient to a T-stop as well.