Ever since the 100D came out, I have been planning to upgrade from a 70D. The only reservation I've had is AP1 vs AP2's feature gap dramatically affecting my road trips. I eagerly arranged an AP2 test drive when 8.1 came out. I've had 17,000 miles in the last 8 months with AP1, and just finished around 150 miles of AP2 driving in a S P90D with firmware 17.11.10 (the car had 17.11.3 but the service center applied the update while we were doing paperwork) Overall TLDR Parity Rating (compared to AP1, 8.0 17.4.14): TACC: 95% parity Highway Autosteer: 90% parity, even glimmers of superiority in certain situations Local/Surface Street Autosteer: Less than 25% parity Extended Notes: TACC: For the most part, this behaves pretty similarly to AP1, only two comments here: Had 1 of ~30 overpasses result in an abrupt slowdown/hesitation. The car fairly quickly (I'd say 50% brake application) slowed 10mph from 75mph and then sped back up. This phenomenon has been documented before. Contrary to the opinion of some, I maintain this is not dangerous though highly annoying and startling. While the acceleration feels sudden because it's unexpected, overall it did not change the speed of the car enough to present a rear-ending hazard. To compare, I found a clear section of freeway at 75mph and jabbed the brake pedal as quickly as I could. The car slowed to 40mph in the blink of an eye, with a lot of ABS sounds. Had one or two situations in the city where TACC inappropriately slowed down reacting to a car in the adjacent lane. As I got closer, TACC corrected itself. Highway Autosteer: Overall, very very usable. I'd call it 90% parity. In fact if you've not experienced AP1, you might feel this is the best lane holding system on the market... Around sharp curves, AP2 does not seem to slow the way that AP1 proactively slows. It also loses holding and goes slightly outside the lane from time to time when navigating sharp curves. Definitely some work to be done here. Stop and go traffic seemed to be handled quite well in terms of brake/acceleration ramping. Cut-ins were not handled as well as AP1. AP1 is a lot smoother and reactive when a slower car suddenly cuts into your lane. AP2 takes a little while to register, and then has to brake a bit more proactively. I had 1 case where AP2 wanted to follow an exit fork. It was sort of a fluke -- I spent a lot of time in the right lane to torture-test AP2, it passed at least 15 exits without diving for them. I actually found that with winding + hilly roads, AP2 is much faster than AP1 at correcting trajectory right after cresting a hill... AP1 seems to have a half-second deer-in-the-headlights moment before making a steering adjustment when cresting a hill, which is absolutely awful for winding mountain roads. AP2 actually handles this situation better than AP1, reacting virtually instantly after cresting a hill. Tracking of worn-out lane markings is actually remarkably good! Auto Lane Change is comparable on AP1 vs AP2. The only bug I observed: The moment you cross the lane line, AP2 shows a pretty jerky lane change animation on the screen. If you don't keep the turn stalk engaged, AP2 is more prone to canceling the lane change because it believes for a split second that you are aborting. In general, though, AP2 does not inspire as much confidence as AP1. With AP1, after 17,000 miles, I actually feel mildly comfortable to take my eyes off the road for a few seconds to mess with my navigation system. I don't feel as confident right now with AP2 -- I've seen it do some questionable things where if there's any cars or curves around, my eyes are GLUED to the road. City Autosteer: It's almost not worth talking about, other than to say it's virtually a joke right now. Don't expect to use Autosteer on surface streets. Now I know what you're yelling already: "But the manual has always said Autosteer is designed for highways, how dare you use it on city streets".... This is mostly for illustrative comparisons. AP1 actually Autosteers reasonably well on multi-lane city expressways, such that I feel comfortable using it as a daily part of my commute albeit with more frequent overrides compared to highways. With AP2, the car goes maybe 15 seconds between attempting to kill me. 90% of the problem is when going through an intersection and the lane lines disappear, AP2 will draw wildly dancing lines and then jerk the steering wheel to follow one of those nonsensical lane lines. If Tesla just solves that problem, local auto steer would be a ton more useful. AP2 does not seem to want to go into "blue car following" mode. Even when it's coming up with completely BS dancing lane lines, it wants to trust those over the car in front. 35mph is not a very useful speed limit in my experience. There's one glimmer of hope: AP2 seems to recognize curbs, grass, etc as lane lines on the screen. AP1 has never managed to do that in my experience. Other / Miscellaneous: The "improved" ultrasonics are, in my opinion, mostly marketing fluff. I saw almost no difference between AP1 and AP2 blind spot detection. It was able to recognize walls maybe from 1 foot further compared to AP1, but I can't imagine that makes a big difference. IMO improved blind spot detection will come when the side cameras are activated. The display of other cars on the road is awful compared to AP1. AP1 can continuously display up to 6 cars: 3 lanes, and 2 cars per lane. AP2 seems to only show 1 lead car in your lane and sometimes the car in front (less reliably than AP1), and it doesn't really show any cars in other lanes. Once in a while it shows a white car in a nearby lane, which is confusing: In AP1, white car means that TACC(or AP speed) is being limited from reaching the set point due to the distance to that car. But in AP2, white cars in adjacent lanes don't seem to have such a meaning: The car doesn't slow down for such cars. Also, randomly white cars blink onto the display without much meaning. The 1080p backup camera is a noticeable improvement over the 720p one. The screen is a lot sharper, and especially in low light there's fewer interlacing artifacts. Overall, though, as an engineer in Silicon Valley, I respect the rate at which AP2 is progressing. Tesla has accomplished a pretty impressive feat, replicating the majority of the MobileEye EyeQ3 functionality on a completely new platform in a fraction of the time it took MobileEye to deliver that solution. I feel confident enough in AP2's continued improvements that this test drive has made me decide to go forward with upgrading my Tesla. But to be perfectly frank: AP2 is not at AP1 parity yet in any category. But at least with 8.1, it's genuinely useful on the freeways.