Nico/Percy? Seriously? That's... sort of refreshing. Most of the PJO fics I read that have Nico are Thalia/Nico.
And about PJO, it was a decent series, but there are far too many similarities to Harry Potter. The Stolls are basically badly done Fred and Georges, Annabeth and Grover are like Hermione and Ron (the Appolonian and Dionysian friends, and they have the same gender too), Chiron is a Dumbledore-like mentor, Percy being the "child of the prophecy" which is sort of like "the Chosen One"... the list goes on.
It's still a decent series - the fight scenes are spectacular, and the Greek mythology is flawless. I just wish Mr. Riordan had bothered to make the similarities a bit less glaringly obvious.
So, to make this relevant to this thread - I hate Travis and Connor Stoll, because they aren't original characters and Fred and George are so much better.