I own and regularly use both 2014 AP1 (80k miles) and 2021 refresh AP2 (5k miles). Plenty of highway and also good amount of two lane roads with hills and tighter curves..
Ap2 lane keeps better than AP1 period full stop no questions. Most evident on hill crests where AP1 predictably fails most hills every single time, and AP2 executes the hill crests perfectly.
For tighter curves there are some curves where AP1 drfits out of the lane wide and gives an alert or gives a take over, while AP2 handles it just fine, often slowing down when necessary.
In the early days of AP1 there were many phantom braking events and those are gone now with AP1. With AP2 on the refresh I haven't encountered any. So both are equal on that in my area.
Maybe in some areas there are overpasses that will trigger a phantom braking in one or the other but I haven't found that yet.
I saw videos of someone in a AP2 getting phantom braking from on coming traffic but I have never had that and drive in similar situations quite a bit. Maybe a camera or calibration issue for them.
If you want to complain about something in the refresh complain about the yoke wheel which sucks, but not AP2 which is a great improvement over AP1 and safer over hills and tight turns (and likely safer for bikes and pedestrians also)
This is definitely not my experience, and definitely not the experience of anyone else I've personally spoken to about these.
I currently personally own.... hmm... 3 Model S, an X, and two Model 3 .... that are legally drivable, at least (way more if you count not usable). The X and two S are AP1, the other S is AP2.5, and one 3 is AP2.5 and other is AP3. The one AP1 S I use the most has AP1 hacked to never need hands on the wheel and never limit speed (up to the 90 MPH limit at least).
All of the AP1 vehicles
far outperform any of the AP2.5 or AP3 vehicles on highway use. Hands down. I know it, the other people who use my vehicles know it, my passengers know it, etc. There's a clear distinction.
To be blunt: AP2.5 and AP3 try to kill us regularly and randomly. Phantom braking is out of control, and their propensity to do dumb things that are completely unpredictable is very high. The phantom braking is so bad on the highway that my wife refuses to even use AP in her Model 3 anymore (which is a clean title, in-warranty, AP2.5, fully unmodified vehicle, for the record). The phantom braking is unpredictable. The dumb decisions AP2+ makes are completely unpredictable. Sometimes it will do just fine in a section, other times it wants to drive off into the median or into a truck. It's barely usable at all. NoA? Forget it. Just adds additional stupidity to the mix.
I'm honestly completely amazed that anyone has anything good to say about AP2/3 given my terrible experience with it on many different vehicles over the years. Like, when people like the above claim it works "perfectly" I'm very inclined to just believe they're lying/trolling/whatever. Like, it just doesn't match reality as far as all of the evidence I have available.
AP1 is
far from perfect, especially outside of divided highways. It's
not great at tight curves or hills on back roads and such, and honestly, it was never intended to be anyway. On interstate highways though, it will beat AP2 every time on usability. Even in the few places it does get it wrong, those places are completely predictable. It's not that it will fail in a spot or situation occasionally or unpredictably. Nope, if you do a route with AP1 a few times you'll know exactly where it's going to screw up, and it will screw up there every time. AP2 also has situations it fails at every single time, but many many more situations where it can work
sometimes, but not always.
People keep bringing up hills and curves. As noted, hills and curves on some back roads definitely mess with AP1. This is well known.
But, I've
never encountered a curve or hill on an interstate highway that caused AP1 a problem. Do they exist? Maybe. But I live in the foothills of the Appalachian Mountains, hills everywhere... and have not encountered such a problem with AP1. AP2 on the other hand.... heh!
For example, I drove a Model 3 just 40 miles yesterday on the highway (80 total round trip). I had to disengage at least a dozen times for various reasons. That same route AP1 does so repeatable and so flawlessly every single time (like, literally hundreds of times) that if I had to in some emergency situation I'd probably bet my life on it. I would almost be comfortable getting in the car, getting on the highway, engaging AP1, and going to sleep with a timer to wake me up before the exit, and be extremely certain that I would get there without any issue.
That's how much better AP1 is on the highway vs AP2. Like in a dire emergency, I know I could get on the highway and let AP1 do its thing without me even needing to monitor if I had to, especially if I know the route.
AP2? Not a chance in hell. I'd be dead for sure. Like, it's not even a dice roll. If so, AP2 somehow rolls a critical miss every time. There's zero chance AP2 would succeed. Heck, even if it was following the AP1 car on the same route I wouldn't trust AP2 to not kill me.
They're just far too different. AP1 is perfect for highway use. AP2/3 just isn't there. It may do better on some non-highway edge cases, but it does
nothing better on the highway than AP1.
Edit: Oh, and yeah... the yoke is garbage also... pretty sure anyone who says it's better is just selling themselves on it so they don't seem like such a fool for falling for it. It's objectively worse in many ways, and at best equal in others... then if you add the clunky touch controls and other changes, it's way worse by far. I tried it for several hundred miles of on and off highway driving. I could
never own and regularly use a car with that interface. If they made the steering ratio what it should be a for a yoke (180-ish degrees lock to lock) then it'd be GREAT.... but a yoke with a standard lock to lock? That's by far one of the dumbest things Tesla has done... and that's saying a lot.