Pretty radical.
Although personally I'm more of a 'used bookstore' kinda guy rather than the 'antique/first edition bookstore' kinda guy, Caliban is a great place to poke through. Tons of potential gifts and 'impress the person you brought over to your house from the bar for a one night stand with your amazing bookshelf' type books. Even better, the place is not dusty. All too often these sort of places get a bit unkempt and cause my allergies to freak. No such problems here.
They even have a graphic novel section! Nice!