I haven't used em but we should have a review coming out this winter over at Blister, I'll update when it comes out. They look interesting though. I played with them at SIA and felt like glide would probably be much better than their grip, but have no real world use to back that up.
At this point (and keep in mind I'm not the most experienced AT guy) the G3 Alpinist LT are my favorite I've been on (although that tail clip sucks massively)
I do know a few people that are pretty stoked on the Volkl Vacuum skins, but I haven't done anything more than fondle them in a shop.