Finally finished House of Leaves yesterday (well, I skipped some of the appendices). This was a solid read and I'm very glad I read it, however, I would not recommend it without reservations. (Aeryk, I would definitely say it is worth plowing through, from where I remember you stopped, you definitely have some more ups, also unfortunately a couple more downs.)
I think that ultimately it is one step too "meta" (it is a book, about a book, about a film, about some scary shit happening to a family that has just moved into a new house) and although all of this presumably suits the author's intent just fine, I found that for me there were sometimes too many layers between me and what I wanted out of the experience, which was the scary shit. That said there are some very interesting experiments with the form of the text where what is happening to the characters really is communicated by the text.
I think if I were to try and read this book again or if I were to recommend it to someone else I would recommend just skipping all of the footnotes the first time through, reading the Navidson Record, then going back and reading the Appendices and footnotes to get the side story with Johnny (which was a major part of the "meta" story, but I felt that it intruded on, rather than added to, the Navidson Record).
My next book I'm tackling is one Thomas Pynchon put out a few years back, Against the Day. It's another burly book and given Pynchon is a literary heavyweight is bound to take me forever as well.