Consumer Reports says (May 2019)

"In practice, we found that the new Navigate on Autopilot lane-changing feature lagged far behind a human driver’s skills. The feature cut off cars without leaving enough space, and even passed other cars in ways that violate state laws [...] As a result, the driver often had to prevent the system from making poor decisions."

https://www.consumerreports.org/autonomous-driving/tesla-nav...