That's kinda oxymoronic. If their designers rock, you'd know what they are doing no?

(I had to click on the tiny tiny "about" link in the footer to find out what they do)

Maybe. You can design for aesthetics, and/or for functionality. Sometimes, "rock" doesn't mean "is good"--think about the negative opinions some people have of [the term, or the actual] "rockstar programmers." In this case, I was thinking about "rock" as in a Hendrix guitar solo--doesn't really get a point across, but doesn't really need to.