Brian E,
I use the fender-mounted original-style mirrors on both sides.
They both were useless until I got the stick-on convex mirrors; then they both are wonderful - I wouldn't leave home without them!
I understand the original fender mirrors can be bought as convex so the stick-ons are not needed, but didn't hear of that until it was too late to trade up.
If you already have the flat ones, just be sure to measure - you can get the convex stick-ons that exactly fit - they are 3-1/2" I think, but be sure to measure - I have four the wrong size
The convex work real well on the street and at the track too for point-bys. Don't let the testosterone-poisoned folks mislead you into eschewing mirrors, unless of course you are one of them
Tom