A Golf GTi is a perfectly good car, but it's a complete backwards step from an S2000 is what we're getting at.
Correct. Whilst I'd never actually suggest a Golf GTI to anyone, I can see it's plus sides, I just don't think it offers anything over say the 330ci for it to be justifiable when coming from an S2000, or any other car with decent driving dynamics (assuming the driver likes cars of this ilk).
It just appears that you are compromising too much, or are being forced into this decision by an external factor that you are unwilling to give us insight of. A whole world of cars could be yours for 7-8K that fill your need for more practicality whilst also offering up a good dollop of driving dynamics. Something a Golf GTi never will.
I hand on heart say this as the owner of a very comparable DULL FWD 265BHP hatchback, I can also hand on heart say that I'd NEVER buy another. This isn't a hatred of FWD, more a dislike for performance FWD. If you want a Golf, get a cheap one, if you want performance... don't get a Golf.