Here is my take...I agree with many this in many critical ways is a step backwards:
1) Controls should be customizable on the bottom, just like Apps are. You should be able to place front/rear defrost, heated seat control, etc, on the bottom row. Removing them to a secondary menu when there is ample space available is no good.
2) Removal of the "cards" is another step backwards. If anything card functionality should have been expanded. Trip statistics and tire pressure now is hidden in a secondary menu. If you want to view this you lose access to the map. Big fail in my opinion. Cards need to be brought back or at least the Trip information needs to be placed on the left side and visible while driving. This affects anyone taking a longer trip who likes to monitor their efficiency, see how far they have traveled, etc. Big loss of functionality and I am really upset at this.
3) Smaller fonts and icons....does Tesla not listen? Many people have been asking for LARGER fonts for years. At least the option to change font sizes. I don't like the smaller autopilot icon - too small. The GUI should be font-sensitive. Looks like it is not. Bad coding. They would need to re-write the entire GUI to support this most likely, which is probably why they haven't done it.
4) Placement of the blind spot camera is not optimal and sort of looks like a hack. I have found myself looking DOWN at that image and not in my mirrors or over my shoulder as I should. Still thinking about this one but I think placing it at the TOP of the screen would have been better. It would be closer to being in-line with your sight. Also it is not fast enough sometimes to display. It's like a 1/2 second or 1/4 of a second too slow to come up. It seems to be a tiny bit variable. Anyway a light in the mirror is still better. Most cars have this now and Tesla should bite the bullet and put a blind spot indicator light in the mirror.
5) Fan adjustment is just a slider. There should be + and - icons on either side of the slider. I find myself jabbing at the circle to try to raise or lower the fan while driving, especially if you have to reach a bit (eg. your arms aren't super long or your seating position is further back). + and - icons would be easier to press. And more accurate.
6) They took away the minutes/seconds display of a song (in streaming anyway). First thing my autistic son mentioned to me. He also said everything looks smaller. Also I don't really like the switch to two-row and thus smaller album art. Yes I know you can swipe up to get bigger art. Still. I liked it better before with the larger album art icons all the time.
7) Many of the screens don't have an X to close it. You have to swipe down or press the car button for them to go away. But it's not consistent. Anyway there is space for the X so why take it away?
8) Current driver profile is now missing from the top of the screen. I liked to know what profile I'm in and be quickly able to change it. The car does not always get it right so I have to manually switch it sometimes, especially when leaving my house - if my wife's phone is still within bluetooth range it will think it is her even when I sit down in the car to drive away with my phone.
I am sure there are other things I will find, but overall I am not happy about this update. I get a feeling Tesla doesn't listen to customers or actually think about functionality needed while driving, especially for those in colder climates where quick access to heated seat control, defrost control, and efficiency information are very important.