I did Curves for about eight months, but found that no matter how hard I tried I never broke into a sweat. And to be totally honest, I got really bored with the same routine every time.
After my membership expired, I joined a local, family-owned gym 5 minutes from my house and I just love it. I'm really limited on what I can do because of my knees and feet, so I do from 20-40 minutes on an ellpitical trainer (virtually no impact!!!!), which is fast becoming addicting!!! Then I do different weight equipment, alternating from day to day. To break the routine, sometimes I do 30 minutes on a bike or walk on a treadmill.
I love it so much better than Curves... but keep in mind that's just my opinion