I looked at those and concluded it's more stuff to lug around. I have three snatch blocks now and I just use one of those and a strop if I need to stand the rope off something. When recovering yourself, the rope actually doesn't move so you can use a mat or something on a rock if it's in the way. It's only when the hook is moving - ie recovering someone else, that the rope gets really punished.
By the way, a rock protector sleeve is available for the Dyneema too. It protects the first 6 feet or so.
Chris