I had a 2004 KGT and now have a FJR13A
The BMW never let me down, ran smooth, had ABS, cruise, electronic windshield, and heated everything, stock in 2004. The bike has a bit more of a sporty nature to it and the "flying brick" motor is bulletproof.
It had some known issues with a 2-4% defect rate in the final drive, Servo ABS crapping out on you, and a 50c o ring failing that causes oil to seep into the dry clutch area. If you stayed on top of your PMs and watched for the known issues, the bike is reliable, fast as hell too (145mph = no problem, rock steady). The suspension and performance was top-notch for a heavy ST bike, I had zero insecurities throwing that bike around twisties, definitely a sporty but heavy bike. The oriental blue color made that bike drop dead sexy too, always got comments on it. Maintenance wasn't difficult and the BMW forum community is one of the best I ever ran into.
The FJR is similar but has a different personality. The FJR is quick, but very smooth and appliance-like, I've had the front wheel go light on me from the torque a few times so the bike definitely has power. We still haven't meshed in the same way I did with the K1200GT where I had 100% confidence in the bike but I'm hoping that will work itself out in time.
Overall I like my FJR more but not by much, and for different reasons, i can still say that the 12 year old BMW still holds its own.