I too, enjoyed this, despite not knowing the Nightingales' music. And weirdly, after having watched it, I felt like I'd had my fill of their back catalogue. The early, spiky, raw stuff was decent, but the solo stuff from the 90s, to me at least, was clearly heavily produced and marketed with having a hit in mind. The man pretty much said it himself. The end result was basically pop landfill, complete with terrible cover art of floppy-haired band man that seemed to have none of the edge or bite of the work of his earlier bands. If he had achieved success at this point in his career, it surely would have been at the expense of losing his core audience and replacing it with teenage girls and Smash Hits covers.
There were some great cameos along the way. Like others have said, the Frank Skinner story was great, and getting Nigel Slater kicked off GQ is hilarious.