I'm not sure off hand about specs, but they feel different - or at least they did when they released the 2014 versions. The 2014s seem easier to stick to the road, less problem getting back on throttle, and the steering input is heavier, more resistant. The 2013s (although admittedly I haven't touched them in months now sadly) had lighter steering, a bit more twitchy. But that's just feel of course.
Would be interesting to know specifically the changes, yeah.