My two cents: Never buy new. I own an 09 and had a little experience with a 10. The improvements of the newer motor were lost on me and the 10 is little loud going in and out of campgrounds late at night and early in the morning. I see the differences between the 08-12 to be very slight.
If I were spending money I would look for the best price on a low mileage well cared for bike 08 or newer (and I too like the GS over the GSA). If that bike doesn't satisfy (which would shock me) you will be in a better position in a couple of years to get one of the new wetheads which I expect will be a game changer.
Buying used I wouldn't let ESA affect my decision one way or the other. I am replacing mine with non-ESA Ohlins.