A friend of mine is a P-car guy, and I've had the opportunity to drive several of his cars over the years. I've been driving Miatas for most of that time period, but recently bought a '17 Mustang GT, so I'll throw in my $.02...
The first Porsche my friend owned was a '99 996 Carerra. It honestly didn't impress me all that much, but it was a Tiptronic. A couple of years ago, he bought a '15 Cayman GTS with a PDK trans. Now this one impressed me... Great balance, great feel... it was like my Miata: you could put it exactly where you wanted it, anytime you wanted to... except it had triple the HP. Very nice car. I've always been a shift-it-yourself kind of guy, but the PDK transmissions are really good. There's no way I could shift as smoothly or quickly, especially under hard braking and clicking off three downshifts into a corner.
Late last year, he traded the Cayman on the Holy Grail: a 2015 GT3....
OMG... I really don't think it could possibly get much better than this. It's just an unbelievable car to drive... everything about it is just... perfect. Precise, composed, thrilling acceleration, and the sound... flat 6 at 9000rpm. It's as easy to drive as my NA track Miata, but it's brutally fast. To quote a movie: "if you have the means, I highly recommend it."
Unfortunately, in the real world, these things are way north of $100k and that's just not happening. As far as P-cars, a Cayman S / GTS is a darn good car, or just pick the newest 911 you can afford. Skip the manual and get a PDK... it's that good.
And Mustangs... we recently traded my wife's NC Miata on a '17 Mustang GT with the Performance Pack. It has impressed me with how good it really is. The Performance Pack (previously called Track Pack) includes stiffer suspension, 19" wheels, big Brembos and a 3.73 LSD diff. Up to 8.5/10ths (which is way fast on public roads) it's really good. Only when pushed to the limit of adhesion does it get a little out of sorts. IMHO it drives better than the C6 Z51 'Vette we had a few years ago. It feels huge, but that's coming from a few years of Miatas, so I'll probably get used to it. The aftermarket is incredible. Full suspension from Ford Performance for $1300. 20hp/tq from a CAI and reflash that keeps the warranty and is CARB approved for $800. It cruises the highway quietly at 80mph and gets 26mpg while doing it. We paid $27k for ours, which had 4500 miles when we bought it, and the previous owner was nice enough to put a decent cat-back exhaust on as well.
If I won the lottery tomorrow, I'd buy a GT3. Since that probably won't happen, I'm pretty happy with our Mustang. We're still tracking our NA Miata, but the Mustang will get out there as well. Probably not regularly, but gotta see what it's got on the track!