I had one of the marlwalker's the first year they came out (late 1990's) and I absolutely trashed the hell out them in one week in Belize. Of course, your hoofing around on nothing but coral there, but I was pretty unimpressed with them. However, they have revamped them and I bought some of the II's and have so far been very happy with them. I do have a wider foot, and the tip about wearing a liner sock is a great one. The first time I wore them I didn't wear some socks and got a blister, but after using a liner sock they are comfortable and pretty much bombproof. Another friend has used the Simms, but they seem to be a little lower on the ankle so I've always been skeptical. Good luck. I like the tip about wearing them one the plane, other than the 5 minutes it takes to get them on and off again.