Holy tolito batman...LOVE this shoe!  I have never been able to wear a shoe with a back, they've either had t have a strap or nothing.  This does not rub, it is super comfortable, they keep my feet at a comfortable temperature.  They are very lightweight, durable and look awesome!  No breaking in...heck, I have to make sure I take them off before I go to bed!  I plan on buying the whole family a pair.  If you're looking for comfort, style and something worth the price, this is the product for you!