I’m about the same size as you – 6′, 170 lbs. My very first bike is an ’01 GS500. I still believe it’s the perfect beginner bike. Physical size wise, it felt great in the beginning (easy to flat foot, with knees comfortable bent), but with 16 months of riding experience on 4 different bikes, I now feel the GS500 a little small – the seat is 1.5-2″ too low for me. I think its size is perfect for someone between 5’8″-5’10”, with 28″-30″ inseam.
Take a look at the review and user comments (a few from me) on this site about GS500: