I joined Curves about 18 months ago, to get back in the swing of exercising. At first, it felt good, like I was pushing myself. But it did not take long to lose that feeling. If you are working and commuting, I had a difficult time getting there before they closed, and their morning hours were too late for someone trying to get to the office. When I wanted to use another Curves facility, I had to get a "permission slip" only good for 30 days, although it was not truly enforced. Hopefully, they have linked their computers, so they can track your visits to any location. Also, I had fulfill a one year commitment, and was only able to cancel through registered letter or hand-delivered letter. No e-mail or phone call.
That being said, if it gets you moving, why not.