I'm on JB and rooted but I never did an FDR before or after the update. I've had random issues and have cleared cache multiple times but I think it's finally time to do an FDR. I think the answer is no, but will doing an FDR cause the phone to lose the root, and will I have to re-root? I've been searching but I haven't been able to find the answer.
I'm hoping to get some battery life back and better 4G connection after the FDR (was better for me on ICS). I do have a titanium backup on my ext SD and the paid version to restore everything easily.