I'm of the mind that anything officially published should be okay, as long as it fits into the game world well. It's not really an issue once I've read it; I've got a pretty good memory for that stuff. That being said, there is a certain build I'll always veto involving a lot of dice throwing to avoid everything.
I have pdf's of most of the core books, and use those almost exclusively just because they're portable, but I also own physical copies as well. I'd feel bad otherwise. I'll be on the lookout for Lost Notes now, next time I get a chance to shop for it.