possibly the vocals? AJ Estrada does have, or rather HAD a little bit of a *lisp* but it was way more apparent on their 1st EP "Old Dominion" than even on "Terror and Everything After" and their recent music.
I guess I can relate, as some bands I should like, like Arcade Fire or Secret Machines (or The Flaming Lips, Radiohead and others whose lead singer kills their music for me), but they just leave me thinking there's something missing in their music, even though on paper, they have elements that I enjoy in music and should like them.