I took these down for a week in Havasupai, and I'm sure glad I did! In and out of water all day, having sandals is a must and these are solid! They really hold on to your foot, feel secure like a shoe, and grip as well as any hiking boots on land, and even better in the water. I got them a few weeks early and started wearing them around for day-to-day business. This is a must because it takes a minute to get used to them and also to get the straps dialed in to where you want/need them. After wearing these only a few times a week for 3 weeks before my trip, I was a little worried about how my feet would fare, but I put 13 miles on them in a couple days with no more wear on my feet than I would expect after that distance. These are definitely my new best friend.
One thing you'll probably wanna do after every few hiking trips is pull all the straps through the slots under water to get the dirt out. If you leave the dirt and sand in there, it will start wearing and fraying your straps!