It's pretty subjective.
To take the recent examples - Data & Janeway. I felt Data was brought back well & Janeway was not. However
even if Data had been brought back poorly, I would have generally been in favour of it, and even if Janeway had been brought back fantastically I wouldn't have cared for it and would have stopped reading Voyager books. Because I felt Data should have come back because Nemesis was a trainwreck and he shouldn't have died there, and I felt Janeway was a horrible character (Tuvix, Endgame, etc) and was happy with the events that transpired in Before Dishonour.
Also, frigging lol at the garbage that Star Wars has become. I greatly miss the pre-yuuzhan vong era when Zahn & Stackpole were writing. Who knew that the dark force that Palpatine and Thrawn were preparing for was 15 years of horrible books.