I own a BA air core, and I'm not sure why it's never gone back to REI, it's not terribly light though it's fairly tough it seems, especially when compared to something like a Neo. I suppose it's fairly comfortable, but I couldn't for the life of me keep my bag from sliding off the thing, on a dead-level tent site no less. Sort of detracts from the comfort factor.

If I were to stripe/dot the thing with silicone, it would probably help immensely, but in the end it's just a bit too heavy for a gram weenie.