Hi, I just wanted to warn you that I take issue with a lot of the reviews suggesting to size up.  I had the opposite experience.  Maybe it's just because I have a slim foot (even though it's a "B" width).  I usually wear a 10-10.5.  I ordered a 9 and my foot was SWIMMING in them - they were so big and the top strap was so LOOSE and it was very uncomfortable for walking because I had to grip the bottoms so tightly with my toes just to keep them on and get around anywhere.
I took a chance and ordered another pair in a size down to an 8 and am I ever glad I did!!  They fit perfectly, not too wide or too long and my arch hits exactly where it's supposed to.  GO FIGURE!!  Nowadays -- sizes from all these different manufacturers are just all over the charts.
I can truly say that I agree with everybody else's reviews that these are the MOST comfortable flip flops I have ever worn.
Spencos are not bad either -- but I wish they had the cushy moldable tops like the Molokinis.