Unfortunately, I missed the actual concert at the Ryman, despite the fact that I live in Nashville. My young son is a Coen Brothers fanatic, I always found their work to be slightly off target with respect to my own tastes.
That was, until, I saw "O Brother..." which I saw several times. When "Down from the Mountain" was shown here in Nashville I also visited it several times.
What music is shown is excellent, I'm a big fan of watching music being created-- I believe that seeing the performers interact adds a depth of understanding of the music. Unfortunately, not every song presented during the concert is in the film, but what's there was very satisfying.
It looked like the film was shot on Digital Beta, or some video format and then transferred to film. As such, it looked a little flat, but the photography itself and the sound recording were both beyond reproach. I'm hoping when I get the DVD release of this film that they've skipped the film transfer and given me the pure video version.