You can feel the difference, but does the difference matter...? that is up to you my friend. On the track it is easy to determine, because you can look at how lap times are effected. On the street, it is all about getting the feel you like and being able to outrun your buddies in the curves.
If you want one, go for it. It is just money.
I liked mine, but I didn't see seconds being dropped off of my lap times. The Slingshot just lacks too much rear traction to be pushed really hard where you might see a dramatic improvement. On the street, it felt better to me than stock and allowed me to run my shocks closer to 40 on softness, instead of 25.
thank you for the help - it sounds like I might like it especially with the softer JRI grand tourings. Might just make it a little more fun on the mountain roads - which is really all I want
thanks again