I like the ones that are oval, rather than round, and mounted on a slanted base.
I have spot mirrors on all my trucks even my wiffs mustang . Long time truck driver, finally let my CDL go but not my mirrors.
I even have them on my two motorcycles. Yeah, you can adjust the mirrors a hair. You cannot adjust them so much that you can see a vehicle in the mirror and your peripheral vision at the same time. All my vehicles, I can do that. There's absolutely no need to swivel your head when you can do that. Best to keep your eyes forward every second you can. And yes, backing up, I can clearly see the lines I am trying to back up between in those teeny mirrors.
In any event, my Ranger has Street Scene mirrors. They are rather small. The blind spot mirrors are what allow me to keep them. On all my vehicles ,the bs mirrors are located on the lower inboard corner. Works very well for me.