My family of 5 enjoyed a visit to Fort Rapids in August 2012. My kids - age 1, 5 and 8 all kept busy in the indoor waterpark (and even my husband loved the big waterslides). We were able to swim at the beginning and the end of our stay (even after we checked out). I appreciated that the water was warm enough that I didn't freeze - and the kids kept busy for hours! The kids area was age appropriate for my 21-month-old, and the slides in the same area were still fun for my older kids. Lifeguards watched everyone closely and rotated regularly.
Our room (Bryce Canyon Suite, sleeps 8) was clean and very nice. We invited grandma and grandpa to join us and they were glad to have their own space/room upstairs. Having a mini-fridge, microwave and clothes dryer in our room certainly made traveling easier - they were small touches I really liked! Strangely, the upstairs bathroom door was pinned open by the bed placement and unable to close, so it lacked a bit in privacy. It wasn't a huge deal, but it did stand out enough that grandma and grandpa didn't feel comfortable using the bathroom upstairs.
If you plan to visit Fort Rapids, don't expect the WiFi to be working, especially on the higher floors. We were on the 2nd floor and it didn't work the entire time. Other guests commented that the connection hadn't worked for 4 days; customer service seemed to indicate they had someone coming to repair it, though it never happened while we were there. Internet is a requirement for me while traveling and I was disappointed that I was unable to connect.
Overall, we'd be happy to return to Fort Rapids Waterpark; my kids are begging to visit again. The area nearby was filled with restaurants and outlet stores; eating out was convenient and we could have picked up anything we needed easily.