If you have tuned it properly, You might was to have your fuel injectors cleaned and tested for flow rate. A difference in flow rate sometimes leads to vibration.
What gear and rpm produces 70/80 mph on your bike?
checked shaft and union joints, also rear wheel main bearing.. think i will get the TBs synced, it only has 19000 on clock so hardly run in.... I have a 1150 gs single spark and its not as bad..