We saw it this afternoon! Its definitely a slow burn movie but Diane Lane is fantastic and her character and Kevin Costner's character communicate so much depth and emotion with just subtle looks between them. There were some slow portions that I think could have been removed. My biggest gripe is that the antagonists are basically just bad to be bad. There wasn't any depth to them or background as to why they were the way they were so it was a little jarring and not very organic to me. Overall though the scenery is beautiful, it was tense and interesting despite being slow. I'd recommend.
Edited to say that its basically the only "new" movie out right now anyway and we are trying to see whatever is currently showing even if it's not a 10/10 just to help support the local movie theater.
Watched this last night and enjoyed the hell out of it.
Echo what the above poster said about Diane Lane and Costner. Costner actually surprised me as I thought this was going to be regurgitation of his Yellowstone role but it's not.
Also enjoyed the time period. Not may westerns we see set in the early 60s.
Definite slow burn but it is tense, captivating, and overall a good watch.