I read other reviews and decided to buy 1/2 size larger.  Good decision!  They're still a tiny bit snug but they've already stretched out a bit and I expect will do so more as I wear them.  I'm using them only for an hour or two around the house to allow for this to happen.  I am somewhat disappointed at how loud the soles are when I walk on hard flooring (ie. tile, wood, stone) which is the reason for the 4 rather than 5 star rating.