I got to play one round with the new ball trajectory & spin and lie effect physics in place. Like many here, I found the impact of the trajectory and spin changes yielded results that were much closer to reality! I was very pleased with the way they affected the game. OTOH, I thought the penalties for light rough were a little severe, and the sand and heavy rough penalties to be significantly overstated.
I had three tee shots roll off the fairway into a fairway bunker. Visually, they were sitting up perfectly, yet showed a 54 to 63% carry with 5 to 7 irons. I had 178 yards in one case to the pin with virtually no lip, and hit a perfectly struck 5-iron on flat terrain... the ball carried 106 yards and rolled out to 118 yards
The heavy rough I thought was overly punitive by a factor of maybe 7 to 10%, while the light rough maybe a factor of 3 to 5%. They seemed to be more on a scale of those we saw in TGC 2. I had the impression HBS' target for this update penalties that would split the difference between TGC 2 and the release version of TGC 2019.
I'm confident that HBS will keep working at it and get this right. The changes they made to the ball trajectories and spin gave this game a satisfying flavor... I can't say enough about good that looked, played, and felt!