I'm using them for Zion... eventually. In the meantime I've been taking them rafting when it's cold so I can wear my neoprene socks or as my fly fishing "boots". Really impressed with the grip and seems extremely well built. Used a handful of times and absolutely no issues. I have a friend that's buying them too, now, off of my recommendation.
This review was written in the old system and had content requirements that are different than reviews written today.