First, and this matters not one whit, because it's subjective, but I like the looks of the FJR better. It's no beauty queen, but to my eye, better looking that the Connie. Remember, that is in the eye of the rider. If you ride one, and like it better than the FJR, then that's the bike for you.
Regarding the motor, I remember seeing comparable FJR and Connie dyno pulls overlaid on each other. I don't remember what year it was, but it was a few years ago. The Kawasaki had a few more horsepower WAY up at the top end, a few hundred to maybe a thousand RPM before fuel shutoff. The FJR curve all the way up to that final spike was higher than the Connie, the whole way. I like to cane the FJR a bit when I'm out for a road rip, and I let the big girl eat, but I'm not getting up near the rev limiter on most shifts. Powering out of a nice curve and winding her up to 6, 7, or 8 grand on the tach is great fun on the FJR. And regarding which model sold more, I see considerably more FJRs out on the road than C-14s, not that it matters.
All that being said, buy what you like, and what you want. That way, YOU will be happy. Good luck with whatever you end up with.