Went with the clearview 8" Clearview curve one. Seems to work ok most of the time but there are times I get more than I want. I guess it just depends on how fast and what direction I'm going vs the wind. Anyway, 8-8.5 is as big as I would go just for looks sake. Functionality probably goes down lower than that.
Still run the stock one, but seriously considering a Klock Works 6.5 due to buffeting with the stock one. Like the look of the stock one, but it is a pain in the a$$ at certain speeds.