What i don't like is that when you pull on the straps for ...
Meh.  The device is hefty and seems well constructed, but it's also thick.  It has two rotating heads with 3 ball-shaped pressure points for massage that rotate simultaneously for a while and then rotate in the opposite direction.  What i don't like is that when you pull on the straps for firmer massage eventually the ball things hurt.  Moreover, the only way to really massage your back is when standing or sitting upright.  If you prefer to use it when lying down at night as a get-to-sleep comfort aid it's quite awkward.  The heated setting is not very warm at all.
Rating: 3 stars