I'm on my second K12rs.
Yes they do vibrate some what, more so at selected spots on the tac.
Also, during times of engine braking you will feel some buzzing.
After a while you don't even notice it.
The bike is built like a truck but it's still quick and fairly flickable. A fun ride on back roads, and not too bad for long rides on the 4 lane.
Bottom line: I'm not sorry I bought either of my K12's. They're fun to ride and well built.