I came from several Concours 1000s and all I can say is the C14 is like an electric motor compared to the C10.
Does anyone find it weird that people always want smooth-running bikes to be ever more vibration-free and "shaker" bikes (like Harleys) to vibrate more? Why can't everyone just appreciate their bikes for the things they do well and quit obsessing over the things their bikes don't do as well? Cripes, the C14 is nearly a full-on sportbike with luggage -- evaluate it in that context. Does it accelerate like a sportbike? Does it corner like a sportbike? Does it brake like a sportbike? And can it cruise comfortably down the highway with all your gear in tow? Then it is what it was intended to be: A sport-touring motorcycle !!!!!
I've been purposely staying out of this thread, because I've been battling the bad vibs from my C14 from the first day I bought it, and don't really have anything positive to contribute. But now, you've sucked me in, thanks.
Some C14's vibrate more than others. My C14 is far worse than my C10 ever was, even when the C10 was at it's worst.
When I first got my C14, I could not ride it above 4K RPM for more than 2 minutes without my hands going completely numb, to the point that I literally could not feel the brake or clutch levers when I grabbed for them. Shortly after that, I could not feel the throttle in my hand, which results in not riding.
Limiting the C14 to only riding it under 4K RPM is not a good answer either. I don't expect the bike to be completely smooth, but there is a point where the vibrations are just too much. Mine was there, but I've made some progress with it, to a point that I could ride at higher RPMs for longer periods, without my hands going totally numb. Recently I made a change that made things worse (a minor setback), but I do believe it can be fixed.
I do have a problem with those who don't experience a problem saying 'there is no problem'. I'm not trying to sling mud here, but for some, there really is a problem with the bike. And as one would expect, due to the potential can of worms it would open, the manufacturer will not even begin to acknowledge there might be, or offer any help in resolving it (believe me, I've tried, and I'm not the only one).
Personally, after spending a lot of time looking into this issue, I'm less inclined to think it's a mechanical balancing issue, and more of a fuel mixture + fuel timing and ignition timing issue. I still have a long ways to go before I'll put this problem behind me, but so far, the things that have made a significant impact were things that affected the intake and exhaust flows. It was an unexpected side effect of the changes, but very real.
And for the record, mine really starts vibrating / buzzing at around 3500 RPM, with the peak at about 5K, and no real decrease from then on.