I've only read one, but it was quite unlike anything I'd read before - old guy, depressing grind of a job, alcohol and rough women - but a rawness and authenticity that you don't often get. At the time I was very interested to learn that he was effectively writing of the life he'd lead.

There's a whole stack of comment below on judging him-as-a-person - but if you read widely you'll be well aware that many books are worth reading despite the character flaws of their authors.