So, this was a good episode to say the least.
This one introduced us to Quibble Pants, a caracter who really did not seem to like the other Daring Do books because of some realism issues. Himself kinda covered some of the bad aspect of this episode, mainly due to the fact that he was a bit too harsh on that aspect of the books and he kinda got repetitive at some point in the episode and it kinda got ols. But I do understand that the writers wanted to showcase a caracter that is like someone who really can critic a lot of the things in a story, just like some diehard fans in this fandom. He kinda covered the side of this fandom that likes the earlier episodes and that is truly accurate.
And that, of course, all led to this greatly executed moral that everyone can look upon, because it does make a point in that some of us like things in a series that some of us might dislike and Quibble said it all by himself, and that helped his caracter I'd say
And it was certainly funny at part, like some of Quibble's remarks early on in the adventure (before they somehow got really repititive), and it kinda got immersive after a while (in the Daring Do adventure that is)
Also, I'm surely not the only who liked the end-credits there, it kinda maked me remember of some other cartoons who did that already.
So you know, it was kinda good, but not the best for sure
TL;DR: Quibble Pants might have been too harsh and repetitive on the realism and all, but his caracter was realistic and they surely nailed him in some way. Then you add the humour and the immersive Daring Do adventure, then yeah, you got Stranger Than Fanfiction, a nice episode.
Rating: 8.5 to a late 9/10