while I don't know "how much" a roadwing shock will improve a 'liners handling,
I do know how much a Progressive 465 shocked my friends 'liner. IMHO
, the percentage of improvement was greater w/ the 'Liner than the Roadie. His bike is an '06, bought new, very well cared for, & not ridden hard/ abused. Steve[my friend] is a big guy like me. Riding w/ him, I'd notice the rear end was very busy[lot of swingarm movement, squatting, etc] We tried more pre-load, etc,etc.
He had nothing to guage it by, so he thought this was the norm. I convinced him to buy a #465. I installed it.It's not as easy as a roadie. The difference REALLY WAS amazing !!!! The overall ride quality, how planted the rear end feels now. You gotta ride it to believe it
I've had both shocks on my bike, #465 & the roadwing. Both are a BIG improvement over stock. I see no reason you wont experience the same improvements my friend did