Double Take Mirrors has definitely done some research and testing with these highly popular foldable mirrors. For one they are hardly noticeable when riding, and two I was able to loosen my mirror, fold it down and tighten it into position while standing up on a single-track trail not even looking at what I was doing. And if you are using a GoPro, it is easy to fold the mirror back up and look into it to see if you are recording or not. The ease of use here is well above average.
