Rick, I am 47 and I do have both bikes... I do enjoy a good romp on the 12S but find myself more and more drawn to the "swiss army knife" like abilities of the GS. I can hang with most every bike in the tight stuff and I have no desire to race along on the straightaways.
My constant riding buddy and I have toned it down a ton (since I can not afford a ticket for at least 2 more years!) and the GS is a bike that the Cops just simply LOOK THROUGH... they can't see you! And the GS fits the bill almost perfectly.
They group I ride with (see Triple Crown) usually has quite a few GS's and here and there the odd 12S (Steve, Tomasa, Rob S. Tim and I) there are a couple of HP2S's and the rest is a mixed bag of all years, makes and models. The GS in capable hands (i.e. IvanTT) is as good as the 12S and overall, it comes down to one thing:
HOW MANY BIKES CAN OR DO YOU WANT TO OWN!
No bike can do it all 100% but IMHO, the GS comes as close as any bike I ever owned has come so far. I love it and I have made the decision that it is going to be my keeper as a street and touring bike... I have a decent sized road trip coming up in which some remote areas will be explored... I would not want to push the 12S through such a scenario - the bike is to beautiful and to valuable for such an endeavor... I would hurt me to ride that bike over gravel roads and see the piss chipped out of it...
Go and see if you can find someone who lets you ride his/hers while they ride your bike... you might be able to buy one after that
