IMO, its really not that big of a gain, and sure is disappointing when you are wide open across a lake trying to be your buddy.
I was geared down 2 teeth on my top sprocket with my 600 twin. Was too much.
But, that was me and how I rode, if you never get on a lake, or want to go over 90ish, you could go 2 teeth down, but I would do it on the lower gear, as keeping the overall diameter of the gear larger is a benefit. When you go down on the top gear, that one gets to be a real tight bend for the chain, which will decrease efficiency.