If you find a 10 second car to be underwhelming, then obviously you need a 9 second car. Luckily for you, Tesla makes one, and it is also quite reasonably priced for its level of performance. For those of us who don't need a 10 second car, the new Model 3 Performance should have more than enough power. The main complaints I, and many other people, had about the old M3P, were the mediocre suspension, seats with inadequate support, and too much of a falloff in acceleration above 60. Tesla has significantly improved all of those issues..05 in the 60' is worth about one tenth. I swapped to lightweight 18's on mine and the difference in 1/4 mile times was less than a tenth. heating the battery makes the biggest difference. I guess we'll have to wait and see what the new one does. If it's a full half second quicker and runs 10.80-10.90, we're talking a 4-5% increase in acceleration, which I find to be extremely underwhelming.
Regarding the grip in the Model S Plaid versus the old M3P, I totally agree with you. It sounds like that situation will likely be reversed with the new M3P.