So not being able to find a pair of the Rasslers in a size I needed I thought I'd give their other water shoe a try. I ordered a pair of the Astral Hiyaks a half size bigger than my normal shoe size (they only come in full sizes). These already have some insulation built in and the soles are the same rubber as the Rasslers which many have said is as sticky as the 5.10 rubber. My biggest concern would be support as I have a weak achilles that I'm nursing. I'll post an update once I've had a chance to test them. Found a place with a 10% off code so for $103 I figured it was a no brainer as I can use them kayaking if they don't work out for slot canyons.