I think we have confirmed here via hook and crook that both sizes work on the bike and some have switched to those sizes permanently. Most say they went up to "increase load capacity." Whether they do that w/o any compromise is still a question mark in my mind. I know for a fact that the speedometer and odometer will be affected but I can't speak to the ride quality. My honest opinion is that handling (on the street at least) would likely be mildly worse overall.
A wide rear tire means more tread on the road, making the motorcycle want to push through turns instead of go around them. This can lead to an understeer
Wider front tires will have the opposite effect of a wide rear, and can make the bike more responsive in the corners (oversteer
). This could lead to a twitchy ride.