The new DFW movie is now out & I went and saw it. It's fine. Jason Segel does a fine job as the muse. Nothing terribly surprising or revealing (I watched it w/o having read the Lipsky book.) More a movie about depression and existential angst - in a believable way - and less about the work which is appropriate.
Re: the movie & music. I'd believe if DFW was a Pavement, Magnetic Fields, Tindersticks fan (though it would be kind of diminishing) but I'd be blown away if he's a Felt fan. It just doesn't fit. It was nice to hear Felt in a movie regardless.
Also, the movie had me reflect on the highest point of DFW fandom in my life. I interviewed for medical school at Case Western and one of my fellow interviewees arrived late to the interview (it was a two day thing). He was late because he was an undergraduate at Pomona (is that right? maybe not but it's one of those schools) and he was in DFW's workshop and they were workshopping his piece. A very reasonable and legitimate reason to show up to your crap-shoot med school interview given the uniqueness of that opportunity. He let me see his copy of his story which had DFW's markings on it. DFW had three colored pens that he used to make revisions. There was a system which was like red = grammatical comments, green = stylistic comments & blue = something else. I regret not taking my fandom bit further and asking him if I could copy it.