C'mon, that's too high a bar. I was there a few months ago (went twice in a week and spent some non-trivial time). While, Dussman has unparalleled selection of books (it's a 4-storied bookstore after all), they are also a gargantuan gift store (the 5th floor, and throughout the other floors). They have a dizzying array of expensive crap to lure consumers. I was there in November, and by Jove, was it teeming with shoppers.
That said, I still loved the incredible bookstore, and the co-located English store. Not to mention the huge vertical garden, with some 600 plant species. Definitely worth visiting, whether you're a bibliophile, or not.
Notably they don’t consider themselves a bookstore. Their claim is “kulturkaufhaus” which roughly translates to “culture shopping center.” They have a large section of DVDs, Music and other stuff. Their comic book section is pitifully small, though.
