I believe the main engine differences are the head, cam and different ECU and injectors..
~1kw bump in power over a STD 09 and better fuel ecomomy claimed..
I'm sure someone has fully researched it maybe they will chime in.
BTW...it looks like they use 2 different injectors between the 2 cylinders(one is black and the other is gray)..interesting..wonder if that is how they solved a possible different fuel requirement for once cyl vs the other..I know on mine the front cyl seems to run a little leaner than the rear ased on the plugs. Maybe that is why the 2010 and earlier 800s seem to run rich..have to run the rear cyl rich in order to have the front cyl not be lean? Maybe the ECU isn't set up to be able to program in bank specific fueling? Ah just thinking out loud lol.