Very comfortable.  The only thing I will say negative in the way of comfort is that if you're planning to walk longer distances in them, they tend to slide off (because they are silicon-y or whatever it is they're made of is slippery) just a bit, making you feel a bit like you might lose them.  The slight heel makes them a bit dressier than your regular slip on sandal and also adds to the comfort for long-wears.  I wore them in Las Vegas on the strip and found them great.