I really only noticed the radar speed signs falling into line with the speedometer, it certainly made a difference there, I like having the accuracy.
I don't do a lot of highway riding, I tend to avoid it, but I think the V7 gears are quite tall.
It should be easy enough to calculate the difference 2" makes to the circumference.
The tire width dimension is important, as I said mine is almost touching the swing-arm on the RH side, i'm sure I will find the paint worn off, easy enough to shim it over a mm or two though.