Did you go to the one in Lombard? Or did another location just open?
These places have been around quite a while -- the oldest one I recall is the Lahaina, Maui location...and then about 5 years ago, one opened in Puerto Vallarta (which has since renamed to "Paradise Burger" or "Burger on the Bay" -- I can't remember exactly).
I kind of equate these places to a TGIFriday's...nothing special but fills the need.
And I concur about Jimmy Buffet.