I thought the songs were alright but the live show seemed really off. I was dragged by a friend who thought the same thing. There's obviously something about this band though. There were quite a few A&R weasels checking out the band.
I believe it was their first American shows, their first big attempts at picking up bigger distro deals stateside, and there were probably a ton of people like you who didn't really know them/their songs. I could imagine they were probably nervous/slightly shitty as a result, which is a bummer. They have a pretty solid footing on the charts over here in the UK ("Pompeii" peaked at #2 over One Direction and under Justin Timberlake) and their die hard fans at the show went insane for them, so I imagine that'd be a more comfortable show to play than a showcase for A&R people/SXSW wanderers.