We did this around thanksgiving. It was pretty busy and the parking lot at the visitor's center was completely full. When I'm trying to get my nature on I guess I prefer to do it without a bunch of screaming kids and barking dogs.
The trail itself is fairly flat and wide. There are great views of the lake and the interpretive signs are nice to read It's fun being in the tunnels even though some of them smell like pee.
For some reason I didn't think the trail actually led all the way to the dam, well, it does! Too bad dogs are not allowed on the dam. My pooch and I had to hang out in the cafe's outside seating area while the rest of our party checked out the dam.
While I'm glad I did the hike, I wouldn't do it again. The Arizona or Gold Strike hot springs hikes are much more interesting and much less crowded.