Overall, a decent experience and nice trip!
We decided to spend a night here over President's Day weekend with our almost four-year-old daughter. We drove in from Dayton. We've previously stayed at the Kalahari in Sandusky, a Great Wolf Lodge in Wisconsin, and a very nice waterpark resort in Gatlinburg, so we did know what we were getting in to by choosing Fort Rapids over, say, the Great Wolf Lodge in Mason, but the price difference was significant and we knew our daughter wouldn't mind most of anything we'd mind anyway. One thing that's important to remember about coming to a place like this is that kids don't have many expectations-- and the things that bothered me made absolutely no difference to our daughter, so I'm betting she'd give the place a 10/10. 
Pros: 
-We liked that there were different types of rooms here. They have standard hotel rooms, bunk bed rooms for kids, and villas. If you are staying in a standard room and not a villa, you'll be in the "tower" part of the hotel, which is really just like an older Holiday Inn that has been redecorated in the western theme. 
-We had no problems with the staff. Our check-in was smooth and even though we were told we couldn't check in until 4pm, we got in early and the young man at check-in let us in to our room early (a little after 2pm) because housekeeping had just finished. We also had no unpleasant interactions with any staff members. I felt that housekeeping was very polite and they did check in once we were in the room to make sure it was okay for us, and they were always polite in the hallways. The first aid crew at the waterpark was great when my daughter scraped up her hand and they were very kind to her. The hotel had activities running all day for kids, including a karaoke in the lobby and milk and cookies with storytime after that. The young staff member who ran it (I believe her name was Nala) was very polite and nice with the kids. We saw management all over the place and even had the interesting opportunity to hear management and security speak with a group of teenagers in the lobby about their inappropriate behavior. We thought the staff were very friendly and helpful and we liked that management seemed to be walking the building constantly. 
-The waterpark had a devoted area for young children and even though this area was for kids 12 and under, it was mainly parents and young children. We spent all of our time there and there were always at least three lifeguards in just this area. 
-There's a hot tub for adults, which is always nice. 
-Our room was a standard hotel room but had some nice touches. There was a flat-screen TV in the "bunk bed area" of our room and I thought the mattress was very soft. I did a thorough check for bed bugs, as I do at every hotel, and saw no bugs or evidence of bugs. 
-The room had a minifridge and a coffee maker, and there was free wi-fi throughout the hotel. 
-The hotel had an arcade-- a little overpriced but nice for when the kids get bored with swimming. 
-The hotel's lobby was very nice and had a constant large fire and a number of soft couches. It was nice for relaxing in the evening. 
Cons:
-This is in a weird location. It's literally in the middle of an old industrial park. Normally this doesn't matter much, but it means that there aren't any quick places to pop out to for a dinner or breakfast or even a grocery store. I sort of felt like we were in the middle of a sketchy nowhere area. This did mean that we had to eat primarily at the hotel because we didn't feel like driving all over the place to find a restaurant. If we ever come back, I'll bring some food and plan to store it in the minifridge, and I will also bring some breakfast foods.
-The hotel food is expensive and not that great. We ordered room service the first night because we were in between swim times at the waterpark and got a pizza and chips and cheese sauce for $25. The food was hot but not overly tasty. We weren't willing to venture out for breakfast so we decided to hit up the breakfast buffet. There were a lot of choices but the food was only decent. That was very pricey and I wouldn't recommend it for the price. The convenience is nice, but you'd be better off just packing donuts, cereal, etc. and eating in your room. 
-I would not get the bunk bed room if your children are older children, like maybe teenagers. The beds were packed pretty much on top of each other and I have to imagine that it'd be somewhat claustrophobic in that tiny bottom bunk. Also, our bunk bed on top had no rails to keep a person from rolling off, which can be scary with a smaller child. 
-Bring your own pillows. I had read this from other reviews but forgot mine, and I was very sorry. The pillows are literally the worst pillows I have ever slept on. They are little tiny squares and they feel like a bunch of old t-shirts wrapped up in a pillowcase. They are so lumpy that I considered just laying straight on the mattress. Our daughter actually chose to roll up her Mickey Mouse blanket and put her head on that rather than put her head on a lumpy pillow. 
-The room only had one tiny garbage can. I read a few other reviews that said the same thing and didn't think it would matter, but we were there for less than 24 hours and ours was almost overflowing, especially after we ordered pizza. 
-The main TV in our room was very old. It was a Zenith and not a flat-screen and had pretty poor picture quality. 
-The waterpark could have been cleaner. We stayed on Saturday night until 7:30ish and came in on Sunday morning at opening and there was still some of the same trash out near the little-kids area-- cups, a napkin floating in the water, etc. Also, you definitely want to bring your own towels-- the waterpark towels were very tiny and probably didn't absorb much water. Also, the waterpark lighting at night was VERY dim. There were burned out light bulbs all over the place and while the little-kids area was well-lit at night, the rest of the park was very dim and almost hard to see in a few places. 
-It can be loud at night. We had a lot of neighbors who were in and out and slamming their doors, and while the walls don't seem overly thin or anything, when the doors slam, they slam hard and it's loud enough to wake you. If you have little ones, I'd bring a sound machine to maybe muffle that. 
Overall, we'd go back, but I wouldn't pay more than we paid this time (we didn't have to pay for our daughter's waterpark pass because she was so young). The main hotel tower is older and the rooms are just not very updated. Bring your own pillows, bring your own towels, and bring some snacks and drinks.