To me, 911 Porsches are not really exotic cars, not like a Ferrari. Might be different for the GT3? Perhaps. But it's ultimately just a faster version of the base car, much in the same way as the M3 is. Not purpose built from scratch.
Don't get me wrong, I'd love to be in a position to own one, and I know I'd be in pure automotive bliss. But if I truly could live out my fantasy to the max, I would like to own something along the lines of a Ferrari or a CGT. Not a 911.
OP, if you are in a position to try, get an exotic. Live with it for a few months and if it ends up somehow being less than what you expected for whatever reason, sell it. Depreciation should be minimal if you buy wisely and use with discretion.
What have you got to lose?
2009 E90 M3 ED
2014 X1 28i