Simon, are you on V17?
the current move is to put all the techref available interactively. You on a parameter and the text from the tech ref will come up. I think future efforts should go into making that interactive resource contain better information.
The Maya Help appears voluminous to me, but after observing numerous Maya users at 11 sec Club I don't think it is a complete solution either.
Consider this quick random check...
I look up "Save As"
the Maya Help takes me to:
huh? buried in the text is a use of something similar to "Save As" but not an explanation.
But Maya's Help is not a bad one, but who would write all the extra explanatory information? Who actually knows enough about A:M to do that correctly and and can write well enough that no one will complain in the future that the techref is inadequate?