apias:

Driving characteristics are not so easy to improve. Just look at F1 and the differences in handling of various cars. If this were easy, we wouldn't see that to the degree we do. Porsche has a much bigger head start in that regard. Which is easier to catch up on and surpass?

Of course, these things are not so easily predictable. Remember Ed Colligan's famous, "PC guys are not going to just figure this out. They’re not going to just walk in." statement. Well, it turns out that "PC guys" did just walk in and figure it out. So, who knows who will walk in where and eat the other's lunch.

In F1 maybe, but definitely not in road cars. In fact, Porsche's highest-end GT car has been getting called boring in many comparison reviews to things like the R8 and 570S. Being that the Mission E and Tesla aren't making track models, I wouldn't expect a Porsche to offer much more by the way of driving characteristics than a Tesla. After all, it's not like anything think the Panamera is such a great driving car. It's a nice driving car, but nothing memorable. Does it drive better than a Tesla? Maybe, probably, I don't know, but it still just drives like a big sedan or wagon. I'm sure plenty of high-end wagons handle just fine, like an RS6.

These days, just about everything has really good driving characteristics because we're reaching a plateau. Porsche will need to compete with Tesla on daily driving and usability aspects more than Tesla will not to compete with Porsche on drifting characteristics. 

Tesla will also really need to step up their interior and luxury. Model S has a $20K car interior. Total trash for such an expensive car. It's pretty much why I won't buy one.

And of course, it all depends how the generations overlap. If a Mission E comes out 3 years into the Model S cycle, of course it will be better, but then the Model S will trump it with the next generation.