I've had my ShapeUps for just about a month now. At present, I use them exclusively on our treadmill, trying to keep them clean (it's still snowy and muddy here). I have to say, most of the other reviews seem to be correct. The shoe works muscles (calves, hamstrings, lower back)that I'm not used to using when I walk, and it seems to force you to walk more upright, improving your posture. They DO take some getting used to, though. When I first put the shoes on, they felt downright weird, and as folks have said, there is some muscle soreness in the beginning until your body gets used to them. I can't speak to weight loss, at least not yet. I have a wide foot (9 1/2 E), so I was concerned about the fit. I bought a half size larger in regular width as suggested, and they seem to fit well with maybe just a little sliding in the heel but not enough to be an issue. When I change into my well-worn NB's, I feel like I have newspapers tied on my feet.

Update:Well, I never did get used to these suckers and ended up trashing them. I won't say they made my back condition worse ... just added other aches and pains. One other thing: the uppers surely are not durable. The leather will scuff if you just look at it too hard. Don't waste your money as I did. Stick to your NB's.