The standard ones should be pretty good for vision but you do need the convex glass in them. If they are loose it would be worth checking how they are fitted to the door. Someone had put mine on with self tappers after the car was painted instead of using the proper mounting plates on the inside.
The replacement mirrors you buy now have a plastic mounting instead of the original alloy ones and they break very easily, probably some kind of modern safety idea. Woody at the wedge shop also has some little metal inserts to use instead of the nasty modern plastic parts that break very easily. Got some of his on mine now and the mirrors are rock solid.
This is a mounting plate that just fits inside the door for the standard mirror.
This is the base of a modern replacement showing how they break and are fitted with self tappers.
This is an original alloy base showing the plastic part that breaks.
These are the metal parts from Woody that replace the broken plastic part in picture 3.
