You also have to remember the technological changes that are around now as compared to what they had then...we have nice electronic and 'smarter' mechanical components now
So the Audi 90 comparison is slightly outdated...now back to the engine discussion. I say for the goal, the two are very close in requirements for getting there and sustaining it. Be it I have played in depth with both platforms. The 4G63 isn't some mysteriously bullet proof engine. Like all engines being pushed, it comes down to having the right techniques/formula to making them live. That and being extremely anal upon machining and assembly
Now choose which car you'd rather have.