Apart from the cp, which is very rare as an end user of /b/, I find it entertaining. There's a lot of crap to wade through, but some of the humorous content really is quite funny. 4chan seems to have contributors that really get the chaotic-feeling, disjoint sense of humor - whereas Reddit seems overwhelmed with puns and catchphrases (OK /b/'s obsession with "rolling" (looking at last digits of post number) is just as lame). I enjoy the "deviant" stuff, too, if only to marvel at the strange things people get up (and perhaps off) to. And why not, if it's an interesting experience? The raids are sometimes amazing examples of performance art (and fit the sense of humour rather well).

As another user pointed out, viewing "best of" is probably a more efficient approach, and let's you avoid some of the crap. But there's something enjoyable about being there, in the moment something is happening.