I've had a pair of these shoes in blue/silver for a few months now. I like them so much I'd wear them everywhere if I could get away with it.  I don't know if my muscles are getting any special toning from walking in these, but I do know that my feet, knees and hips are comfortable. I wear these shoes for intense 3+ mile workouts on a treadmill and for casual wear. I like the appearance of the XF version of Shape-ups, because the sole has a lower and less clunky profile than the original Shape-Ups styles. (That said, I also have a pair of the original Shape-Ups, in a solid black leather "work" shoe, that I wear for my shifts in a volunteer activity where I stand and walk for hours at a time. They are also very comfortable and my feet and knees aren't hurting even after a long day.)

Last week I got another pair of shoes in the Shape-Ups XF line, a similar style to this one, in black. So I can "sneakily" wear them with black trousers where silver sneakers would be inappropriate, but a nice black leather lace-up shoe would be acceptable.

Obviously, shoe fit is a very individual thing, but I would recommend that anyone try the Shape-Ups, because I've had such good experience with them.