Well, I've never owned a Porsche, but I've ridden in them plenty.
I would say that the new Mustang would be a good car, but having realistic expectations is really important. Ford is doing some really good stuff, and the fact that a Porsche owner is considering the new Mustang, is a rather interesting turn in the Mustangs customer focus./appeal.
Anyways, I would think that a Porsche owner would be happy in a new Mustang, as long as the OEM struts/shocks are replaced a.s.a.p. Ford really doesn't do enough with their stock Mustang struts/shocks to control body motions, and I would imagine that is something that Porsche owners would notice right off the bat.
The performance package should be a great value (other than the shocks/struts), with great brakes, good wheel & tire package, and good value.
Please follow up on this thread, should you decide to get a Performance Pack 5.0, and let us know your opinions based on driving a Porsche.
2012 GT Premium, Brembo PP, MT82, 3.73s, Blk/Blk. Bama 93R, Koni Yellow Rear Shocks, Hawk Ceramic pads, Luxurious & Plush Floor Mats