Very comfortable. Size must run a little small, the sandals were given to me as a gift from my wife and she took a chance and ordered them a 1/2 size larger than I normally wear but they fit perfectly. I can just slip them on and off without adjusting the bungee cord fastner. I've read that some people find the footbed uncomfortable but it doesn't bother me at all.
I bought a pair of these this spring and have been wearing them quite a bit. They are really good looking sandals. I find them very comfortable and quite functional. They offer good support. I have had stones come through the drain holes, though. Overall, these are a very good choice for an active adult.
I purchased a pair for summer use and took them with me on vacation to Disney World in Florida. I initially planned to wear sneakers and socks, but surprisingly I wound up wearing the sandals in all the theme parks. As for the water slots, after a few wears your foot molds into the sandal and you don’t even feel them. I found these to be a very sandal for the price.
As a woman with wide feet, I've found that men's size 8.5 fit just right in styles that are "unisex". I wore them several days & found the drain holes in the sole caused raised blisters on the bottom of my feet. My solution was to wear the sandals with inserts (you can buy at any pharmacy or dept. store) & that did the trick! At the end of the day, when your feet are at their biggest, these sandals will still feel comfortable.