funny, i had the same reaction
It's not like there's much about Nancy Spungen's life story that I respect. But that book put me inside her head and I found it a scarily familiar place.
I dunno if I ever read a Lennon bio cover to cover. I think his autobiographical album "Plastic Ono Band" told me the story better than any book ever could. I did read Barry Miles book about Paul McCartney which really brought home the point that McCartney was a lot smarter, more literary and more artistically experimental than a lot of people thought. Definitely an *authorized* biography but I didn't mind.