I bought a cheaper model a few years ago and I love it. Yes sometimes I get the flicker but I am only looking at it for a few seconds to either check the trailer or for backing up so really do not have an issue.
The only issue I have had is getting the monitor to stay where I want it. I can see the benefit of getting the model that has the monitor in the rear view mirror, I hate having stuff on my windshield.
Funny thing the other day; I was taking the truck and camper to work. Turned on the monitor but not the camera and then had to sit on an off ramp. As I was sitting there the monitor came on and showed me a moving picture of the same off ramp, then I see my truck and camper. Freaked me out, turned out it was a RV passing me. Made me step on the brake a little harder as I thought I was moving.