My Mom joined Curves probably little over a year ago. She goes weekly and is very pleased. I've been so pleased with her dedication to it. (Now if I could just be like her in that way, ugh)
Id like to join a Curves myself. But, living out of town it just isn't easy to drive so far when I want to go work out.
I think Curves is a great place where "real women" can go and not get that feeling of intimidation some do while at those other gyms mixed with all sorts of people.