Don't know bout the 750 but I went up one tooth on the counter shaft on my GXS1000 and I like it much much better. Tamed the beast a bit but still has gobs of power. Also a bit better on the top end on an occasional cruise.
That's like having the rear go down by 3 teeth.
Seeing the torque is so strong on the 1000, I had no trouble taking off in 2nd gear, so I think for the 1000 as tourer focused, that would be the right move.
Getting a bigger toothed front sprocket means that the chain adjustment range is better as things wear, there is then room to slide the wheel backwards.
I have changed both sprockets on a Bandit 1250 or 2 to get the wheel to come to the middle point of the adjustment range as per stock chain length.
The wheelbase stays the same in that case as I was happy to keep it that way.