I've owned one since '97. It has its pro's and cons. What was interesting that I found out was one day I had an avid weightlifter try it out one night and he could NOT master the motion of it. It's a totally different animal than free weights, because you don't have one arm helping to stablize the other in holding the weight, which is a plus in strength. Would I ever buy one again? Prolly not, because the seat kept breaking, but the newer ones look a lot better in quality. I did use it a lot for a couple of years and I can't say I hate it, but I don't love it either.
One thing I would recommend to anyone looking to totally transform their body...and I mean TOTALLY...is P90 X. LOL, I know it's cheesy as hell to do videos, but it is no joke. I dropped 50 lbs in 3 months and was in the best shape of my life and had a ton of energy and strength. All you need is a pull up bar and a pair of dumbells (25-35 lbs.) and it doesnt cost a million dollars and you dont have to replace parts and it doesnt take up space. Quite a commitment though, being as you need to spend an hour a day, 6 days a week, but damn if it ain't effective!
Hope I was of some help.