I mixed the commentaries last week. They shot the commentary to the unrated version of the film - it's about 30 minutes longer than the theatrical cut (1hr36m) and, man, it really seems a lot longer than just over 2 hours!
I thought it was a pretty ambitious film and some of the songs were fantastic (A Life Without You, Beautiful Ride). They say in the commentary that it took them 18 months just to write and record all the songs and John C. Reilly's voice is really great.
Pscates, maybe you blocked it out, but you neglected to mention the male frontal nudity scene. You get, like, three times more in the unrated version!
Overall, I think it's a good movie. A bit uneven, but definitely worth a look.