depends on what you plan to do with it. don't forget the weight difference between motors will play a role in how the car handles as well. the 1.8t will be great for quick gains of power through electronic and turbo upgrades, but the vr6 will be better excepting of long term gains (turbo, porting, etc.). it's all a matter of how extreme you plan to go with your modding and what your overall goals for the car are.