Being vertically challenged I always looked at the GS and certainly the GSA as just too big. Then I sat on a GS, hmmm, then I discovered the lowered suspension, double hmmm. It became a no brainer. It ticked all the boxes.
but which one?
I went with the GS because I was still not absolutely certain I was making the right choice (the competitors were the r1200r and the s1000XR); I ruled out the GSA just because it still just looked too big, and that big gas tank was high weight that even if I fit, I did not want to wrestle with it.
Man, I got the 2016 GS in Racing Red and it is by far the bike for me, and I wonder now why I didn't get it instead of the 09 r1200r I had. It is just a wonderful bike to ride, quick nimble. The GSA would have been good too, I know, but the GS is more bike than I deserve, and the GSA would be even more so. I just don't need the extra crash bars, or the extra fuel, or the bigger screen, or a fancier seat. It is an interesting dynamic though. You see GS envy on other bikes' forums, even other BMWs, but you never see any remorse or comparisons between the GS and the GSA riders. There are some minor differences between the two, as listed. If you think you want the , to me, minor things that make them different, or not, go for one or the other. Either way you will feel you are riding the flagship of the BMW motorcycle line.
IOW, if you get the GS, I don't think you'll wish you had the GSA, and vice versa.
and you're 75% there---you like the way they look! Me, too.