I have seen and enjoyed both movies, have not read the book so can't say which is truer in that sense.
I find it interesting that the OP mentions the hair in the new version as a problem. I feel exactly the opposite. The thing that has always bothered me the most about the original is that they are all so clean. Kim Darby and Glen Campbell in particular have clean and seemingly combed hair as they ride for days and sleep on the ground. Their clothes (and John Wayne's) don't much get soiled either.
I also feel that Jeff Bridges is a much more convincing drunk. My wife and kids had trouble understanding his slurred speech but I caught most of what he was saying.
The new version is much grittier, not a feel good movie.
But again, I like both.