I think Rey has more force potential than the others we've seen, Anakin included, and I don't mean that as an insult. I figured it was intentional. The second time she fired a blaster, she hit someone from several yards away. She did the Jedi mind trick without any training. She had a an extremely detailed vision upon coming across Luke's lightsaber. My theory is: Spoiler She's the chosen one. Not another chosen one, because they were wrong about Anakin. For me, her level of ability doesn't go too far, but it comes close to going too far. It's walking a fine line, so when for someone else it's too much I can't exactly be surprised. I don't want to debate whether she's a Mary Sue per se; I think the Mary Sue concept can be useful for explaining one's position, but when it gets treated as an ironclad rule it's just in the way. If I liked a character who happened to be a Mary Sue, well, I would like that character.