Well, I'm going to get a lot of flak from those who've been waiting for updates and haven't gotten any.
As mentioned before, took a long road trip on a 2021 LR AWD MY, with a recent install of 2024.3.10/12.3.3 in there. However, my daily driver, a 2023 LR AWD M3 was sitting in the garage, without being plugged in or anything. And, while on the road, the 2024.3.15 update got pushed to the car. Wasn't even in the area, but 12.3.4 is what it had.
So, today. made a dinner run with the car, some distance of 10 miles total, local roads only. This is the report of that.
First off.. Maybe it's the difference between the cars, but 12.3.4 seems slower and a lot more hesitant on UPL from the local housing development than 12.3.3. I mean, no cars approaching from either direction, and the 12.3.4 car just crept, and crept, and crept.. and eventually sped up and turned left. At the next stop sign onto a somewhat busier road with yellow stripes and all, this performance was repeated. 12.3.3 was very much faster on the turns.
Second: Somebody mentioned that curbs showed up being wider in the display. They're right, they are. As others have mentioned, this may be an attempt to prevent curb grinding and all. Neither car has made a suicide attempt on curbs in any case, so no difference except that the curbs looked different.
Third: I tend to run around with the Auto Max setting set. Hey, it's something new and shiny! And, on both cars, when they were running 12.3.3, not only did the cars keep up with traffic, they went (usually) somewhat faster than the speed limit. Unless it was a parking lot or things looked hairy, in which case both cars on 12.3.3 slowed down; really, the kind of behavior one wants.
The M3 on 12.3.4 seemed different. For one thing, in a 25 mph zone, the car tended to actually stay at 25 mph for extended periods of time, especially if there were no cars in front. On relatively long stretches of this, the older algorithm (?) would kick in a bit and the car would speed up a few MPH.. but the delay in doing so was definitely different than 12.3.3.
If there was other traffic about all going somewhat faster than the limit (30-35 in a 25 MPH zone), the Tesla would go a bit slower at first, then notice all those cars up ahead, then speed up to match, but not catch up, with the other cars.
So, as we all know, the main change on 12.3.4 was to snag all those "Unicorn" MX's, MS's, and such like from long ago and far away. But it does look like somebody's been doing some tweaking. Not major, but something.
I know that there are those that claim that the Software Is The Software And Shall Never Change Until A New Release, but I think I've seen times when the FSD activity changes after a drive or three. I'll drive around a bit over the next couple-three days and put up another report.. especially about highway driving.