FYI on cameras that OP mentioned briefly.
Higher rez = more graininess and/or need better memory and better lens and better software encoding
Higher frame rate = less blur, but poor performance in lower light
I wish cameras were a silver bullet. Enforcement aside, getting clear video of the incident (front and/or behind) AND plate numbers AND clear leading up footage AND undistorted view of main activity AND other objects in view to give sense of scale and speed is hard.
I am in the camp of just have a dummy camera as a deterrent. It is too much work to have a device charged and calibrated and all that when it does not work necessarily. Besides, the camera will not make riding next to 45 mph traffic pleasant