I like 'em. They keep your socks and trousers clean. If you do step in a bog hole or river, and you move quickly, they can slow the water up enough to keep your feet dry. The one bother is the way they tend to smear the muck upwards as you walk, so you sometimes end up with mucky thighs. Because of this (and the noise) I sometimes find myself walking in a weird cowboy way to avoid them rubbing off each other. But I don't mind!
Mine are a cheapie old pair - maybe Wynster, not sure. Stiff enough to stand up, so you can leave them a little loose for venting.