Ran through the two episodes last night. It's very good, and following the source material well, with decent updating. The original book is from the early 80's, and a little darker and meaner, and I think it might've worked better if staged in the 80's, early 90's, but what can you do?
Solid 8-8.5/10 for these two episodes.
Fx should option more of Elmore Leonard's books, he wrote in a way that was very adaptable to the screen.