I just purchased and installed the K2 system. I would like more magnification - narrower field of view. Can the lens be replaced or an external one added? I am not very well versed in optics. I really liked the image from my Swann Bolt cameras. Their field of view is slightly narrower at 110 degrees and has much less fisheye distortion - my pet peeve with action cameras. With the speeds of motorcycling, most of the action is not withing a couple of feet of the lens - or you've got serious problems.
Other than the field of view, and maybe the option of adding an external microphone for optimal placement, I am very happy with the K2 system.