My 2 cents worth...
I've read this entire thread. I had an 07 GS for 3 years, and less than a month ago sold it to buy an 07 GSA.
Well...I can tell you that I was ready to upgrade the GS with Ohlins, and the GSA already had them. I wanted the larger fuel tank, and the GSA has it. I wanted the extra suspension travel, and the GSA has it. So...I guess you can say I did it because I WANTED TO!
I like the GSA better. It's physically a better fit. What's the real difference between the GS and GSA? Since I'm the only person who's opinion matters to me on this issue, I just like the GSA better.
But they're both great bikes.
Drink coffee...do stupid things quicker.
His: '07 R1200GSA,'01 R1150RT
Hers: '93 K1100LT, '03 F650CS