(Full disclosure: I have not read House of Leaves yet.)
House of Leaves is undeniably one of the most pretentious works of literature I've ever read.
But it uses that pretension to give readers a look inside themselves as well.
This rather matches up with a little idea of mine - that pretension, at the end of the day, is just another type of aesthetic, to be used and exploited at the will of the writer. Even so, pretension's definition, strictly:
characterized by assumption of dignity or importance, especially when exaggerated or undeserved
Can this be said to be accurate of House of Leaves? Is its dignity and importance exaggerated or undeserved? I'd say not based on the sheer swirl of thought and intelligent critique, of both love and hatred for the book. A book has no importance until someone attaches importance to it.
Based on what I've heard of House of Leaves and The Familiar, Danielewski sounds like an auteur - someone of a very singular and unique vision. In this respect his work is bound to be divisive, for the thing about a singular vision is that everyone else is merely looking inside. We can't fully understand it, so we either accept it and find ourselves stunned at the depth of thought or we reject it and call it pretentious rubbish.
I can't wait to read House of Leaves for the first time, myself. I've heard so many good things about it. It sounds like a fascinating novel. The works of auteurs often fascinate me - they are so intricate, such depth of thought behind them. Calling their quality one way or another is impossible because the mind behind it operates on a different... level, or perhaps mode, than yours or mine.
Similarly, I can't wait to read Ulysses for the first time. So many works of art, so little time!