I initially got the 8.5 and found them too close so I returned for the 9. They're soft and comfortable, but they stretch out in no time then flop around.

Update:
Third time's definitely not the charm with these. My first and second pairs, although they stretched, remained wearable, and so I ordered a third pair in a different colour, same size. These started off flopping around! Very disappointed because I really did like the orange combo, but they have to go back.