Jonnie,
I'm 5'7" and 27" inner and 196 lbs. I've no problem with the 1200gs in the lower position. I had no problem with the adventure (low seat) and no problem with the 1150gs in the low position.
If you're coming from a lower bike to a gs you'll find it the gs very high until you get used to it, but you will get used to it. When I got my F650 GS Dakar I bought a low seat (from the standard gs) and lower suspension arms, two months later I took them off and I now ride it standard.
Honestly you'll get used to it.
Garfieldus