As I currently own both a 2017 FJ09 (NorCal bike) and a 2018 R1200GS (SoCal bike), I fully agree with Maximo's commentary. I love both bikes equally and for all the positive reasons he cited.
For what it's worth, my few dislikes on the FJ:
Primary rider seat attachment mechanism (cheap/loose)
Strange clutch sound when disengaged (appeared after about 18K miles)
Slight hesitation off-idle (probably a tuning issue on my part)
Dislikes on the R1200GS
Heavy when moving around - not when riding
ODB port holder/harness/connector (cheap and very fragile)
Access cover for battery/ODB port - attachment method (rubber grommets fall out easily)
As a side note, I got the FJ to turn-in properly by dropping the triple clam down about 3/8 of an inch - amazing difference - highly recommend this to everyone regardless of weight/height etc..