I recently stopped going to Healthtrax after about five years. Part of the reason was laziness on my part; I wasn't going often enough to get my money's worth. Another reason is that the pool is always crowded. The water aerobic classes are over- full, and it is nearly impossible to do lap swimming. Healthtrax has affiliated with Silver Sneakers for a while now and I think part of the crowding is due to a large number of Senior Citizens. I don't think it is as bad of a problem with the Nautilus machines (the treadmills do get busy, though).
Healthtrax has a nice facility and it is kept very clean most of the time. The locker room does get messy during prime hours. It is also expensive. To a certain extent, you do get what you pay for; it's nicer than most local clubs, but I'm ready to sacrifice some of the amenities for a more economical membership. Since swimming is my primary focus, I am going to look elsewhere.
Finally, I have to mention the staff. Most of the people are really enthusiastic about what they teach, and they care about the patrons. This is really nice if you are just an average person looking to get in shape..