Seat Height
I just bought a low suspension '09 GS last week. It is the factory option. Comes with a low seat, and shorter shocks. I have a 30" inseam, and am 5'7"
I tested a regular sized GS with a low seat. But the low suspension works better if you want your feet on the ground vs. being on your tippy-toes.
I now have 750 miles on the bike, in 4 days of ownership. I am very glad I went for the low suspension.
I also have an '06 RT, but the GS is more fun to ride. This is my first GS, but I can see why guys fall in love with these things!