Fine, then give them both Fs, don't call 100% manual lane changing "perfect".

The reviewer also experienced frequent highway disengagements by the SuperCruise system which you can observe in the video, yet still rated it higher than Tesla, citing only one Tesla accident. That's also weird!

I have a 2015 Tesla S 70D with Autopilot and I use the lane changing feature. It works rather better than I expected when the lane markings are clear.

Perhaps the fact that I did not expect it to be good and therefore went into using it rather carefully and sceptically helped me use it safely. The feature I was specifically interested when I specified the car was normal traffic aware cruise control.

I always look in my mirrors and so on before triggering the lane change and when the markings are not clear I pay even more attention. I use it more on British motorways than Norwegian ones because the British ones have much clearer lane markings and both I and the car can see them better.

The display of lane markings in the dash makes it very clear when the system is confident about the information it has and I bear that in mind when I trigger the lane change. I treat this feature as just another feature of the car, like anti-lock brakes, etc., good when used properly, dangerous when pushed beyond its limits.

I remember when anti-lock brakes were introduced that some motoring commentators worried that people might allow themselves to get into more challenging situations than they would do without ABS and thus be at risk of going beyond what the automation could handle and lose control. It seems they worried unduly.

Lane keeping, lane changing, etc., are features that any sensible driver can use to advantage when it is safe to do so. If the driver is not sensible then I'm not sure that they will be any better or worse when using or not using the feature.