This is just an excerpt from the whole movie review. Again, just Kristen's parts. Click the source for the entirety of the article.
"And Fanning's weak effort is a crying shame, because Kristen Stewart is a revelation as Joan Jett. She absolutely fucking nails it. I'm sure it helped to have Jett herself on set for reference purposes, but that doesn't downgrade the bravado of the performance. From the moment she appears on screen she's a nuclear missile homing in on rock and roll stardom, who isn't going to let any motherfucker stand in her way. While Fanning has the showier role in Currie, Stewart's got the tougher assignment. Currie is living a cliche rock lifestyle because she doesn't know any better; Jett's living it to prove that she can, and because she knows she has to in order to get what she wants. The self-awareness, and self-assurance, in Stewart's performance is amazing, and completely unpredicted by anything I've seen her do before. It's a performance that to an extent even saves the film. With a lesser actress in the role, the Runaways would have been a total train wreck, as opposed to the merely OK movie that it is. I'll even go a step further. Kristen Stewart does a better job of channeling Joan Jett here than Joaquin Phoenix did of channeling Johnny Cash in Walk the Line. She's that damn good.
About the only thing I can think to compare Stewart's performance to is Joseph Gordon-Levitt's in Mysterious Skin. I had zero expectations for either of them heading into their respective movies, and came out the other end strongly suspecting that they might in fact be among the best actors of their generation. Gordon-Levitt's proved me right on that assumption since; I can only hope Stewart shakes Bella out of her hair and gets a chance to do likewise.
Basically put, the Runaways is just all right. Stewart's performance aside, it's nothing special. It isn't daring enough to be more than a formulaic rock biopic, but despite all the teenage drug use and the brief lesbian scene between Stewart and Fanning (c'mon, you knew it would be in there... did you really need me to tell you about it?) it also isn't entertainingly trashy enough to be a legendary Gaggle of Starlets flick. It may, in fact, be the exact midpoint between I'm Not There and Satisfaction.
If it ends up doing for Kristen Stewart what the band itself did for Joan Jett though -- make her realize what she wants and what she's good at, and helps her get there -- then it'll all have been worth it."
Via kstewartfans