Well, I don't know know how to test the fps of the video camera but from what I have experienced before in ICS, when you move the camera very fast from side to side, there is a lag in between frames while recording and while playing the video, while on the JB version, as per testing it right now, I think the issue is solved, I have swayed my phone from side to side very quickly while recording, with no lag even in the playing of the video.