The P100D is going to be way more clapped out being almost 10 years old now. The new model 3 has plenty of superior and innovative features like adaptive damping, track mode, vented sport seats, rear passenger display, etc. Oh, and it comes with a warranty.
As far as driving experience goes, the new Model 3 performance is simply better.
https://www.tesla.com/model3-performance
We have to be realistic with ourselves that these cars are getting old. A Tesla Model S is not a fine wine, it doesn't get better with age.