It's all good.
I understand your angst completely; I parted with a really nice running, extremely nimble and fun Aprilia Caponard to get my GT. The Capo was over 100 pounds lighter, had great flick, and inspired great hooliganism when riding it. Lovely bike, comfy for my wife on the back as well.
That said, the GT's so fast it makes my eyelids flap inside my helmet! I go through my familiar turns 10 to 15 mph faster than ever before, and with a sureness of line that tells me there's much, much more speed available.
Like your GS, the Capo was an old friend when I traded it off; The GT is a hot new romance, and brings with it the joy and thrills of learning an entirely new bike, with half again more power.
Don't regret trying something new, the GT's a hoot.