[Nexus 6P Accessories] dwswager:
Benson Leung is doing a great service by identifying to users whether various Legacy to Type C adapters and cables use the appropriate pullup resistor. Unfortunately, most people have misread his statements and even worse, drawn erroneous conclusions. Benson Leung Amazon Profile (Reviews)

What the Leung Reviews Actually Tell Us:

Whether the reviewed product uses the correct pullup resistor base on Type C specifications or not.

For whatever reason, the Google Chromebook Pixel (2015) will not charge with a cable that has the wrong pullup resistor.

The Google Chromebook Pixel (2015) might attempt to draw 3A at startup and depending on the port it is drawing from, it might burn the attached port.

What They Tell Us w/ Respect to the Nexus 6p:

Absolutely nothing

While we can infer that the Nexus 6P will believe that the attached facing port can deliver up to 3A, the review gives us no indication about how the attached devices (6P on the C end or the port device on the legacy) will react. We know the 6P behaves better with these cables than the Pixel. Link for a post and video link for getting 3A from an Anker Type A charger.

How to use this information:

If you desire a cable or adapter that adheres to the Type c specification, buy the ones Mr. Leung reviews favorably and avoid the ones he reviews unfavorably.

If you desire the possibility of getting more than 2.4A from a legacy charger, buy the cables that Mr. Leung tells you have the wrong pullup resistor. This includes having a single charger to charge your Nexus 6P and other phones and devices that need less than 3A all with Type A cables. It has been confirmed that you can get 3A safely to the 6P using these cables with Type A chargers. We hope manufactures will provide 5V/3A capacity, if not rated, chargers.

Recommendations for using these “Out of Spec” devices:

Mark them. While it is ignorant to shun these cables because you don’t understand the potential benefits they can provide, it is also ignorant to use them unknowingly. Also, if you have an issue, it makes it easier to determine if the cable is the problem.

Test your specific devices with the cables before deploying them for use.

Is it Safe to use these Cables to get 3A from a Charger through a legacy port charger?

First, a charger has a rated capacity, say 2.4A and a higher actual capacity. What that means is that the manufacturer certifies the device to supply enough power for a device that needs no more than 2.4A Because of sample to sample variation, the device must be designed to supply more than 2.4A so that those at the bottom of the sample will still meet that 2.4A requirement. For example, my device might need to be designed to output 2.7A so that I have a 99% confidence that any single randomly selected charger will be able to produce 2.4A. Hence, a device rated at 2.4A, outputting more than that is not unsafe. It is normal and expected It is only unsafe when the device exceeds it actual capacity leading to thermal shutdown.

A USB charger does not blithely output full rated current continuously. It is also important to understand that the attached device (the sink) controls the draw. This is why you can safely use the same charger to charge a 900mA device, a 1.5A device and 3A device. Battery charger does not require a full power!! The 6P will draw up to 3A, but does not require 3A

We know that these cables advertise 3A to the Type C port. That is, the device believes can draw up to 3A. The Nexus 6P seems to behave well when 3A is unavailable. It appears to work as it is supposed to by monitoring vRd on the buss and moderates it’s current draw to maintain the reference voltage. This is how it precludes overdriving a charger without the charger having to trip it’s own over current protection.

I have little need to connect my 6P to my computer and so I don’t use these cables connected to computer USB ports. I have the cable in my car and the 2 adapters in our other vehicles where I know there is a Type A to Micro B cable always available. Since the only at risk component is the $10 charger, if I ever have an issue, I really don’t care. However, to date, these have worked fine everywhere I’ve tried them.