I've had my 2012 3 wheeler since December of 2012. It can be disheartening to hear all the tales of woe in one lump. I've had relatively good success with mine aside from some remarkable gaffs that Morgan themselves created.
What have I learned?
1 - Never lug the motor. That gives you wicked torque spikes that the compensator just cannot handle and it is there to protect the tranny. Keep it above 3,000 rpm
2 - Never redline the motor. It gets flaky above 5,000 rpm anyway so just don't bother.
3 - Always use a high quality synthetic oil made for V-Twins. They run hotter.
4 - Add an active oil cooler. Even a passive one would help.
5 - The stock battery is an under powered waste. Upgrade to something with more cranking amps that will fit.
6 - Replace the incandescent headlamps with LEDs. You'll be able to see what you're hitting at night much better.
7 - Carry as many tools as you can that makes you comfortable. I carry metric and English as the car is a true bastard in that regard. I think I'm hauling about 20 lbs worth but it has been worth it. They have all come out at one time or another.
Morgan replaced my chassis on their dime since the motor mounts cracked in three places. That thing is a torque monster. I think the breaks may have occurred during startup when the motor goes from zero to 100 ft lbs in an instant. My opinion. The newer frames have much stronger gussets and should withstand that particular abuse.
I still have the car. I have fixed or repaired most everything on this Blau Beastie. The motor is solid as long as you stay in its range. The transmission is sweet. All of the British bits that were added to those as well as other indescribable parts from who knows who are the dodgy parts. All of that stuff breaks.
I still have the car. It bears repeating so I did. After all of the fixes, it has continued to run sweetly and, dare I say, reliably. It is also great fun.
There you have it. One man's opinion.
Happy motoring!