My wife bought these for me.  I like wearing them around the office.  They take weight off your knees and put them on your quads, glutes & hips, thereby keeping your quads & glutes engaged even if just standing still.  I like walking in them on our daily lunch break walks.

One big negative:  I would have given this shoe a 4 star rating but the tongue is too short and not wide enough.  For a shoe of this retail price category this is very disappointing.  I have a low instep and the tongue slides to one side. It also barely makes it to the top of the shoe, which is an even greater problem if one has a high instep.  When the tongue slides over to one side, the hard shoe string eyelet section at the top of the shoe digs into my foot.  This is very uncomfortable and I have to untie the shoe, re-position the tongue and re-tie the shoe.  Hopefully they have fixed this problem in later models, but it is something to be aware of when purchasing MBT's.

Possible other negatives:  1.  They do not have any arch support at all, which is okay because you can use any type of insert you want then to adjust accordingly;  2.  They also have a little bit of an impact when walking in them.  They tend to cause your heels to hit the floor or pavement harder than normal when walking.  However, the rolling action of the shoe is good for my achilles tendons that sometimes get sore from elevated shoes such as the traditional running or walking shoe or men's dress & casual shoes. 3. You must have at least decent balance and ankle strenght to use these shoes or you could be susceptible to turning (spraining) your ankle in them.  This has not been a problem for me so far.

Positives:  The partial mesh upper does more than just breath, it ventilates your feet.  The air movement through the mesh is incredible, keeping your feet drier and more comfortable.  The traction of the rubger outsole is very good.

Overall I really like these shoes.  They are easy on my knees around the office and help burn extra calories and tone muscles through passive exercise.