I have a 2009 V which I ride in NJ (1500 miles). I recently bought a 2010 V which I ride in WV (200 miles). The 2010 vibrates a little more than the 2009, surprisingly since the 10 has one rubber engine mount. The handlbars vibrate noticeably at 4500 rpm, and the foot pegs vibrate at 5500 rpm. I like both just fine, but my 2009 V runs a little smoother than the 2010. My "opinion" is that different bikes will vibrate - more or less - depending on how well the engines are balanced. I doubt Kawasaki actually spends much effort to balance them, so it's just "luck of the draw."
I love both bikes. If you have a choice, take a ride on each and watch for vibration at 4500 and 5500 rpm. Pick the smoothest. Windscreens are now available for the 2010. Might still have to look for rear bags.