I recently had the KS. What a great bike! Fast, smooth, sporty looking as hell, responsive in every way. Loved it. However, the ergos killed me. BUT, that's just me. I have seen posts from many "older" than I am and ride longer distances without an issue. Probably should have accessorized with the bars and peg extenders. Would have helped... Realize that at that time I still owned the LT. So I had the best of both worlds.
IMHO, you can not go wrong with the S. Take one for a ride. You'll see for yourself. However that said, I love the new GT. It fits my body and my mission perfectly. Good luck.
"The more people I meet the more I love my dog !"
07 K1200 GT deep blue metallic