Based on the fact that you drive a GT4 I would assume you appreciate and prioritize a good chassis and crisp handling over straight line performance or drag racing and both the more practical CS and the more focused CS-S offer this. Otherwise you'd be in something stupidly powerful, German, AWD car (plenty of which to choose)
There's two factors here: performance and cost/future value.
Performance wise and by that I don't mean drag-races or flooring it on the wet but real fast driving through all sorts of corners, the CS-S is already proven *with official times* to be faster than all the cars you mention, BMW 235i, M2, M3*, A45 and just as fast (if not faster) as an M4 (M4 Nurburgring time: 7:52, CS-S: 7:49...) On the latest EVO test it's also faster than the Civic Type-R and guess what, the Focus RS. At this point I'm kind of confused as to what lack of performance you are worried about.
Still, it may be worth noting that there's a considerable amount of extra bhp and torque that is very safely squeezed out of the CS/CS-S/R engines with mere piggyback boxes (no warranty worries) and then I'm pretty sure that with that excellent chassis on offer, you are practically looking at a Porsche killer.
The question about future value and collectability is more complicated and to an extent only speculation can be done. If the CS-S then doesn't become a collector's item (for one reason or another), then it is safe to say that the standard CS would be more highly sought after as it's a full daily hot-hatch, with all the special looks and bits (bespoke aggressive styling, bucket seats, alcantara trim), a 95% similar chassis (uprated springs and dampers, steering rack etc.) yet all the Golf luxuries still in place.
Honestly, given the GT4 is there, it doesn't make much sense to have another very similar (meaning non-practical unless you never have/want to carry passengers), track-focused car as your daily. Buying it with an expectation of making money out of it is of-course a very different topic but I doubt anyone could guarantee you that.