We have hard floors and in an effort to prevent feet problems in the future, I ordered size 10 for my daughter who normally wears 9.5.  I thought I would try them because I adore Kamik rain boots which have outlasted all other rain boots on the market.

The slippers are just as great.  Even though they are almost a size bigger on her, they never slip or fall off and she will be wearing these all winter.

The only con is they collect all the dust and white dog hair on the floor which I simply clean off when I vacuum with the hose attachment.