Personally, I strongly dislike self-insert stories. I wrote a few over the past three years, and reading them now, I noticed that they were awfully mediocre in terms of creativity and originality.
I'm ashamed. All I ever did was use the original story's plot and insert my "original character" into it. And since I already knew how the story would unfold, I made my OC do things that would make all the characters like her. She was an empty corpse, a puppet that was readily available for manipulation.
I hate it. I used her for my own personal gain and I feel terrible. She didn't deserve to have no substance. She deserved to be human, she deserved to have her own life story to live out and tell.
She deserved to be a good character.