Skittish? What the hell is skittish? It's not even a term to define the handling of a car. If anything it's more about ride control (as in ride comfort with regards to damping and springing), but not handling.
Lots. Porsches of old were called widdowmakers. Porsches these days are rather more predictable and sorted. Indeed, the main reason Porsches got such a bad press for many many years (in the UK at least) was because of their unpredictability at the limit with the rear engined layout. With a mid engined car it'll tend to behave very very predictably, albeit a little more quickly than, say, a front engined rear wheel drive car.
But no one has ever called a Porsche skittish when discussing handling and balance.