I wouldn't give up on trying to find a solution. My MS is the most stable and smooth vehicle I have had the pleasure to own (other cars that I have are no slouch either - NSX, Porsche Cayenne, etc).
If the instability happens are specific speeds, I would look at the wheel balance situation. You can balance the wheel or even do an "on car" balance that accounts for the axels and bearings. If the vibration is more in your hands than your seat, that may point to issues on the front wheel. Last but not least, inspect the tires and rims for belt damage or out of round rims.