Love Reef Cushion flip flops, but I swear they have made some changes to their sizing!!  Their latest styles all seem to fit tighter and be a bit smaller/shorter than those from previous seasons.  I once had plenty of room, but now find that my heel is hanging off the back.  I wear a size 11, so if they continue to downsize, I may have to find a different brand, as I will no longer be able to fit in them.  A real shame, considering I have worn Reef for so many years now and really like the comfort and support, I have always enjoyed with their Cushion line.