Wind is your enemy.
I tried every pair of gloves known to man...electric, gortex, unobtanium, etc. Nothing helped. Then I zip tied a pair of roost deflectors to my Ducati 996 and my fingers were happy.
I just did the opposite on my 990A. I changed my barkbusters and didn't have time to attach the deflectors. Today I rode to work (8 miles) without the deflectors, just the metal bars and my fingers were freezing at 45* even with heated grips and good gloves.
On the plus side, my new Klim gear is the shiznit!