They have a damn good documentation group, largely because they hire a lot of engineers and teach them the writing bits on the job. I find documentation quality

They have a damn good documentation group, largely because they hire a lot of engineers and teach them the writing bits on the job. I find documentation quality is often directly correlated to the technical understanding of the writer. To write good docs, you need to understand how to write well, of course. But you also have to beta test a lot of (undocumented!) features and become an expert in extracting information from code and engineers. The beta testing and information extraction parts of that are damn near impossible without engineering experience.