When I was learning to drive, my dad took me with him on a day trip about 90 miles away. His truck didn't have a rear view mirror in it. He told me I needed to learn to use the side mirrors. I did learn that day and haven't looked back since (pun intended).
In the clipper, there is no "turning my head" to check the blind spot. I have to use my mirrors.
Towing the FnR, I can turn my head, but it doesn't show me any more than the mirrors do.
Where turning my head is important is when I'm doing daily driving in and out of parking lots. There are a lot of people who will come racing through a parking lot ignoring those backing up. They can appear out of many directions, so looking back gives me the best view of all those directions while I back up. Have avoided a lot of idiots by doing so.