By and large, this is a fairly vanilla documentary; Dave Letterman is a charming but not exactly incisive interviewer. Any sort of U2 fan will hear nothing here that they didn't already know from elsewhere. The musical performances are by and large good versions of some of the newly rerecorded 40 songs from Songs Of Surrender. I was especially taken by the new version of Invisible, a song which had previously left me cold. It's moving and inspiring here, almost touching on gospel. The sequence where Bono and The Edge play a song written especially for Dave Letterman is very sweet; the bond between them is clearly real. It's also the case that whenever Glen Hansard is on camera (singing or speaking), he's a fun and engaging presence. Fans will enjoy it for the music and the behind-the-scenes feel; U2 sceptics may find some of Bono's reflections interesting.