As it happens, I just saw the original True Grit and I like the Coen Brothers version a lot more. It is funny, but the complaint I had about TG (2010) is the ending. It felt really abrupt. I still believe this to be true, but the ending for TG 1969 is worse. Too tidy.
The changes from one movie to the other are interesting. I think 1969 TG has a better plot. There were a couple of improbabilities in TG 10 that were resolved in the original movie.
Nevertheless, I thought Jeff Bridges out-acted John Wayne (pause), no lightning strike, so I guess I'm safe, and the young woman actress was fantastic in the new movie, not so much in the original. Hell, Damon was great too and better than the original.
TG 1969 is 2 hours, where Coen Brothers is 90 minutes. I think the shorter movie helps the plot along a whole lot better.