If you've ever listened to any of the James Lee Burke books on tape or CD and the reader was Will Patton you may agree with me that Will is the personification of Dave R.
Tommy Lee Jones is a native Texan (or so I've heard) and no one portrays a Texan better IMHO, but he's not a Cajun. His delivery is all wrong. I lived in the state for several years and I can still hear the strange patois that a Louisiana accent contains. TLJ doesn't have anything like that.
I thought Marry Steenbergen was a good choice for Bootsy, but I missed seeing Cletus (who will be cast in this role? The Rock? Mickey Rourke? whoever, he'll have to be big).
Overall, I thought the movie was only a 4 - the plot flopped around like a fish out of water and didn't have the normal interesting, yet non-linear continuity that the book typically has.
Hopefully, Hollywood will try another JLB book, "Last Car to Elysican Fields" would be a good choice. We'd get to see some of the best villains from JLB ever.