I will agree with you about the added weight....just went for a blast round the Twisties and the front of the cars still feels jumpy...but suspension jumpy not as the front wheels lifting off the ground like they used to. it turns the corners more sharply instead of understeering into the nearest barrier.
The only reason i can think that the Tyres have added "Grip" is the fact that the Driving Aid isnt actually off when it is supposed to be.
And for the Fact the DA is now always on...I feel i just cant kept the Drifts i was able to do when they where off Before the Update.
IF HCM changes it back to the way it used to be only with a Fancy Interface...then they are going to be charging us M$ points for something the game already had.
But i suppose i will have to wait for someone puts up their review of HCM before i make my Judgments