Hardware acceleration in Adobe Media Encoder vs ffmpeg On macOS, Adobe Media Encoder has options for hardware-accelerated rendering utilizing OpenCL, which seems to speed up encoding time. 

On the other hand, according to the ffmpeg wiki, ffmpeg's hardware acceleration "typically generate output of significantly lower quality than good software encoders". Is this true of both Media Encoder and ffmpeg, or does Media Encoder somehow better utilize hardware for encoding?
Media Encoder and ffmpeg should generate the same quality if given the same encoding parameters.

GPU encoders are provided by GPU vendors. I haven't heard of any third-party implementations. The possible differences lie in the wrappers i.e. the code which initializes the encoder parameters, and written by the interfacing app. There, I would expect ffmpeg to offer more fine-grained choices although I haven't look at AME's offerings as of late.