Yup, my first time out using Autosteer was underwhelming. The car was twitchy / squirrely within its lane when driving on a 6 lane US Highway, and braked way too hard entering a curve I regularly take at 65mph (55 speed limit.). I can drive the car much smoother without making my passengers sick from the twitching. TACC worked as expected, and I will use it most of the time during highway driving, as I did with my previous vehicle.I think people in this thread are expecting way too much of the current AP. I think it's Tesla's fault for making us believe it is a lot more capable/reliable than it really is.
My expectation is that it behaves as an adaptive cruise control and autosteer with some limited additional functionality, such as slowing down in curves that are not too extreme.