Everyone knows Emma isn't a particularly good actor, but she's beautiful and seems like a lovely girl and it isn't ok to say out loud. Hearing her superb costars in Perks of Being a Wallflower try to talk her (and her awful American accent) up was kind of painful. Daniel has a good presence and he can hold a scene. He's not a cookie cutter hollywood hot guy and I think it works in his favor. I like him more for it anyway. I've never had much of an opinion on Rupert's ability, other than I think he'd be fun to hang out with.
Eh? Despite her accent wobbliness, she and Ezra Miller were the highlights of Perks. Perks really seemed like a much better representation of her as an actress than Harry Potter, mostly because the films became so plot focused to fit in everything from the books as they expanded.