No doubt, the Gen II is superior in more ways than are ever mentioned.
Better cooling system
more power
better brakes
better spring rate
smoother
different sprockets to ease stress on the chain
drive mode selector (if you're into that sort of thing)
smoother transmission
comes with a windscreen that is similar to the double bubble
passenger pegs are better damped for vibes
less unsprung weight
better fuel injection, no need for a fast idle lever (it definitely starts better in the cold)
Plus many other things.
All of these little things, make for a nicer bike. Looking at horsepower numbers alone it may seem difficult to justify the extra cost. But if you start to add up these little things like coolant system upgrades, they get expensive quick.
I had no intention of giving up my gen I for a gen II, but my gen I overheated and cracked the head. It ended up being more economical to give it up and get a new one. I loved my gen I, but have no reservations in saying, if you can swing the finances, you need to get the gen II.