I test rode a k1600gtl (2018).
Top heavy compared to f6b. F6b has more torque immediately available at low rpm. F6b is much quieter (2013).
I found k1600 more comfortable. K1600 wind management fantastic. I loved the flip out wings which provided 10x more wind on rider than baker wings.
K1600 twisty handling awesome but affected by vehicle wind on hiway. F6b much more stable on hiway.
Wasn't bothered by k1600 weight at all.
Was bothered by engine noise which really surprised me. Still considering a swap to a k1600.
Trying to find something between my f6b and ninja 1000. May try 2018 wing. Won't consider Eluder or any large vtwin.