I’m not particularly anticipating it, either, but that’s mainly because I’m an EU nerd, and I already have a story about how the Death Star plans were stolen.
That said, I don’t find this a compelling reason to not see it. It’s kind of a Star Wars tradition, at this point, to cast lesser-known actors in newly created roles. I wasn’t a fan of Natalie Portman before the movies-which-I-don’t-admit-exist came out, but I am now (more thanks to V for Vendetta than Start Wars).
