Generally, I like Cobian sandals/flip flops and I own several pairs.  I need extra padding on the balls and heels of my flip flops, so these Cobian flip flops really appealed to me for that reason (and they have some lift without actually have too great of a difference between the heel and the platform of the flip flop).  I am a solid size 9 in shoes and flip flops, almost without exception.  One exception to this are Cobian flip flops; in Cobian flip flops, I take a 10.  I carefully read the reviews on this particular flip flop, and other purchasers had recommended going a size up for the tan ones, but going with your regular size for the flip flop in the rose gold.  Based on this, I ordered my regular size (size 9) in the rose gold.  That ended up being a mistake.  The size 9 just is not comfortable.  My toes are almost at the top of the flip flop, and I have a little bit of room in the back heel, but they just seem too small.  My toes push against the strap part of the flip flop in a way that is uncomfortable.  I read a review saying that the straps would loosen after wearing it for a little bit.  After several days of wearing the flip flop (for hours at a time), though, that didn't happen for me.  Instead, I ended up with sores/marks on the tops of my foot without the strap giving me a little more breathing room for my feet.  I like the padding of the flip flop, and I think it's a cute style.  Because of this, along with the great price on this particular flip flop (less than $15), I am reordering the rose gold in size 10.  I am pretty sure that size will be a much better fit for my feet.