This is a fun hike, but only when you get down to the river.
The first 2 miles or so were pretty boring in my opinion- It's all gravel, which is tough to walk on, especially if you have any sort of knee or low back problems. The walk back on the gravel was especially rough on the body because it was ever so slightly uphill. Once you get down by the river the terrain gets a lot more exciting. You get to climb a bit and jump around/walk through the spring, plus you get a beautiful view of the river for a while. Once you get to the end of the hike there's a ladder that leads you up to the hot pools. Don't stop at the first one because they go back pretty far. The pools seemed to get hotter and deeper the further we went back.
If you want a more challenging hot springs hike with a greater variety of terrain, I'd do the Goldstrike Hot Springs hike instead, which is just across the border on the Nevada side of the Hoover Dam.