I was worried that these would be too big since I usually have to size down for sandals.  I used the Amazon fit guide, and these were great.  There is a slight cushion, so they were really comfortable for me.  I wore them in 100 degree heat on a boat and while playing with the kids in the playground, and my feet felt fine.  However, my friend with high arches tried them on and said that there was no way that she's be able to wear them.