I'm not saying the vr6 is unreliable and I am not saying the 1.8t isn't but the vr6 is designed poorly if you think of a crossflow cylinder head- intake on the opposite side of the exhaust to prevent heat from going to the intake valves because cool air burns better-
the vr6 has the intake at one side of the head (and only one head for both banks of cylinders) and the rear cylinders get hotter air.
the 1.8t is a far advanced engine like the audi/vw v6 with 30 valves the 1.8t has 5 valves per cylinder 3 for the intake and 2 for the exhaust and what it lacks in displacement it makes up for it with boost.
I could say an improperly maintained 1.8t would not last as long as the vr6