Watched it this weekend, and found it a bit disappointing. Never seemed sure if it was driven by the plot or the relationship between the two main characters and somehow fell short on both counts.
Ultimately the mystery just wasn't as "clever" as the scene that was set, the cinematography created the tension and mood, but the script failed to match.
Woody Harrelson was also at best average in it, he was completely out acted by Mcconaughey. That alone just lead to wishing they had spent more time exploring Rust's dysfunction and back story than they did, and given Harrelson less screen time.
It is good, but it doesn't come close to living up to the hype and fawning that has been lavished upon it.