I didn't have any problem with Rey in Force Awakens. She was portrayed like Luke and Anakin were in their first movies, capable and powerful. It's in the second movie where my problems start. Luke lost his friend, his hand and lost a fight against Vader. Anakin lost his hand and lost against Dooku, but more importantly he was starting to lose his inner fight between light and dark. With Rey there's nothing like that. She just goes on and wins, always. If you have a character who always wins, then there's no suspense anymore.
I am kinda hoping Rey would indeed turn to the dark side. Maybe because everything comes so easily for her, she couldn't connect to normal people or their struggles anymore. She would grow prideful and see everyone else as inferior. But I really doubt it happens.