They are really flexible. 390 are more of an all mountain bindings. They aren't a pure jib binding. I haven't heard a lot about them, but the little I did was pretty good. I don't think many people ride them, there may be a reason for that, there may not. Do you have your boots yet?
Yup I bought my boots like two weeks ago. And did you mean you haven't heard a lot about the 390? Those are actually the bindings I'm using right now, but they're 2009.