I liked reading HPMOR and it's certainly among the best fan fictions I've read, but in my opinion it has all the usual benefits and shortcomings of fanfics: It'

I liked reading HPMOR and it's certainly among the best fan fictions I've read, but in my opinion it has all the usual benefits and shortcomings of fanfics: It's based on fascinating ideas and a new perspective on the known world and characters, it has an unconventional story that the author obviously tells in the way he wants. On the other hand it shows a lack of editing. There are whole chapters that don't move the story forward (like a third of the book is dedicated to student battles that just seem like a filler before the author decided how to end the story). I feel like those would all get significantly shortened if this would be a published book with an editor. Anyway, I like reading fanfiction, but I think it stands on its own and it's hard to compare it with conventional published literature.