I didn't post here initially (just created an account two seconds ago, actually) but I did come across the Brooklynian forums while doing some google searching before I moved to Crown Heights. Of course, it was hard to find answers to a question as simplistic as "is crown heights safe?" but the few posts I read here were pretty much the most helpful information I found - even if everyone said basically the same thing.
This is the first post-college apartment I moved into (after living at home in the suburbs for a year,) so naturally I was a little apprehensive. Not scared, really; I just didn't know what to expect (especially since many people older than me would raise their eyebrows at the mere mention of Crown Heights, immediately associating it with violence and racial tensions.) In the end, I moved on impulse because I fell in love with my apartment immediately. That was almost a year ago, and I love living here more than I could've ever predicted!
There's a lot of life here. I personally feel completely safe 99% of the time because I live right on the parkway, where there are always people around, and it's well-lit (and pretty when the trees are in bloom.) I try to avoid walking alone on the side streets after dark, but that's just common sense (and I have friends who do anyway, and they've never had a problem). I still carry pepper spray because I'm a youngish-looking female, but I'd recommend that to any young woman living anywhere in the city, just to be on the safe side.
But yeah, I wasn't expecting to feel as safe or as attached to the neighborhood as I do. I recommend it to young brokesters like myself all the time. Neighborhood pride!