I have a 17 GS Rallye with the 20mm taller Sports suspension, which gives, for me the best of both worlds. Most of the time when I'm riding it's hot so I don't want the extra weather protection of the GSA and I don't need the larger tank. I prefer the sleeker looks of the GS Rallye too, if it can be called sleek, but it's definitely sleeker than the GSA
Both are great bikes, a lot comes down to the cost at the end of the day, I got a really good deal on my Rallye with all the factory extras, so there was no way based on that deal I was going to pay the massive amount extra for a GSA, but under different circumstances the prices can be closer, particularly if you want some of the items that would be extra on the GS that are already on the GSA crash bars, driving lights etc.
Ultimately getting the bike that fits you and you are happiest on is also very important, these bikes aren't cheap and saving a couple of thousand to end up with one that isn't really want you wanted will be a mistake in the long term. Make your decision and then don't take any notice of what anyone else thinks of your choice.
I'm 6' 4" and find the GS Rallye with the Sports Suspension is wonderful, with the 20mm taller suspension I fitted the 20mm Touratech lowered foot pegs that really opened up the riding position while still giving me normal ground clearance. I think the Sports Suspension is just the GSA suspension on the GS, taller and stiffer than the stock GS suspension, but welcome if you ride 2 up and or heavily laden.