From what I have read on the vortex, and the people i have talked to on there they say the 24V is the most reliable when it comes to the motors compared to the 1.8t and the 12v VR6. They havent had any major issues like sludge or anything like that like the 1.8ts had, and the only real problem that I know of on the 12V was the chains, which has not been a problem on the 24v at all. Im just going by what they are telling me, you know more about VWs than me so anything you say i also take into consideration. What common problems do you know of in the 24V?