I've only read a couple of Joe Lansdale novels and a couple of short stories. None of these featured the characters Hap and Leonard, so the title of the show on SundanceTV meant nothing to me. The trailers looked like interesting pulp mystery novel fun.
During the opening credits I saw Lansdale's name and got excited and worried at the same time. The thing I like about his writing is the no hold's bar nature. It's about as un-PC as you can get. I wasn't sure how that would translate to commercial television. Turns out it almost made it. If I had never read his work, I might have been impressed.
Like the characters in the books I read, Hap and Leonard use racial and sexual slurs as casual conversation. If you make it through any of Lansdale's work, you know that in his world words are just tools to get at ideas. Other than that, the language in the show is mostly stripped of profanity. It Suffers for it only because I know it's missing. It's strange, but I think the profanity of his books allows ideas to slip in to your brain easier. Look at the opening lines of Bubba Ho Tep. While you laugh and cringe at the description of an infected bump, he slips in the feeling of helplessness that comes with old age. Take away the profanity and the rest feels flat.

Over all, it was a good show. Not great, but good enough to tune in again.