Well, I'll jump into the fray here! I bought a $9 pair of ebay bar-end mirrors, removed the stock mirrors, and have installed one bar-end mirror so far on the left. Dropped my Givi Tall on a MadStad all the way to the bottom and about 3/4 of the way "back", and there is now only the slightest of buffeting at any speed in "clear air". While following another bike (@karlos) or in freeway traffic, or in high winds, there is more buffeting, but it's muted...meaning, it sort of moves my helmet around softly; it isn't rabbit-punching me in the head from all directions at once causing my vision to blur like it was before.
Bar-end mirrors FTW!
Yes, you do have to consciously look left and a bit down to see behind you (especially when you're wearing a Shoie X-14!). But that little 3" mirror surprisingly gives me all the info I need at a glance. I'm actually getting to where I can just tip my head down a bit and move my eyes left, but that didn't happen until I moved the mirror above the bar; I'd initially installed it hanging below the bar.
Also, there's no way to attach the stock handguards at the bar end; I'm going to experiment with a longer screw and use the stock bar-end spacer where the handguard normally goes.