I can only speak on the VQ engine since that is what I have experience with.

Boost vs N/A.. for the sheer power I'll go with boost but the fun factor went with N/A. Putting down 400+hp boosted was nice at first but it got old and predictable. N/a the sound and the experience was unreal.. with basically a lightweight clutch and flywheel assembly the car was fun but somewhat hard to drive.