If you're wondering what year R12GS(A) to buy : from 2007 onwards there's no servo assisted braking, from 2008 there's the new design, from 2010 there's the DOHC engine. With each generation the increase in power is combined with shorter gearing. The 04-07 generation consumes least petrol at identical speed/gear.
The discussion GS versus GSA is something else. Emotions run high without reason. Both are excellent at what they do. Very much a personal decision.
It starts with this : if you must have the larger range then the adventure with its' bigger tank is the only way to go; are you OK with the GS's range (>200 miles on 1 tank), then you still have a free choice between the two.
The main difference in riding experience is mere physics :
GS : lighter (esp noticeable at low speeds/manoeuvring), lower, highly flickable, screen causes turbulence on highway, faster acceleration over 60mph.
GSA : heavier (esp noticeable at low speeds/manoeuvring), higher, handles well inspite of its' weight, more 'planted' feel, better windprotection.
If you're worried about windprotection on the GS, there's lots available in the aftermarket, so that's not a dealbreaker.
Finally the design differences : black wheels are only to be had on the adventure; wired wheels are available to the GS, but I'm not sure if an adventure can be ordered with alloys. The luggage systems are available to both, though. The frame, front forks, seats, and fairing have different colours. It's these design differences that often make the decision.
To
me, the GSA height, weight and bulkiness is a disadvantage. I don't need the extra range : when I'm out biking with friends, they're always the ones needing petrol before I do. I went with an R12GS (twice BTW), bought a higher screen, and have been happy with my choice for more than 80000miles.
Neither bike is better than the other, just different. Like compairing (let's say) a BMW 3series with a BMW X3 (rear wheel drive only) with identical engine.
They both make their owners happy, just like GS and GSA do.
Good hunting !
