I don't care for them myself. I drove a rental a while back that had them. At night the bright headlights from behind bug me. Plain side mirrors I adjust down a bit but with these I couldn't get the lights out of my eyes.
because they are convex, the lights from behind are not bright at all in the vehicles I've driven. I suppose if you had a sensitivity though, it could be tough. I put them on every vehicle I buy if they don't already have them. On my truck, they came stock and are very large. I hardly use the regular mirrors any more. Those convex ones just provide so much more valuable information. I'm always amazed when I get in a vehicle where the previous driver had the mirrors adjusted to see the side of the car we are driving. Why do you need to see your own car? Madness, I tell ya!
In a funny anecdote, my daughter was having trouble with her 2001 Prius... needed tires, actually. Well, it was just before a trip across country when we moved and she swore her car "Can't go highway speeds". She was really wrong but was just afraid to make the engine rev up any at all. ANYWAY, it was night and I was taking it on a test drive. I reached up and flipped the mirror lever for night time driving (you know, that thing that aims the primary mirror up towards the ceiling) and she was just shocked. Apparently, she'd been driving for a year without realizing that she could dim lights behind her. I consider it a monumental car guy/dad failure and just plain funny.