Mandalas and visualization

[tingdzin]

A comment by Zhen Li in another thread inspires me to ask about others' opinions on the functional role of mandalas as related to visualization. In particular, what do people think of ideas expressed by writers such as Sharf that "visualization" in practices that depend heavily on mandalas tends to be less "thorough" -- that is, less vivid (?) in that the mandalas themselves are doing all the work, and Shinohara, who sees (I believe) mandalas and visualization as being intimately related in that the latter allows condensed practices less dependent on, say, concrete images? I started the thread in the Academic section because non-academics may not be familiar with the discussion, but I'm really interested in it from a practical point of view, and comparing the Tibetan and Japanese approaches to the subject "on the ground".

[Malcolm]

This is a complicated question because the generation stage involves many parts, with bases of purification, purifiers, and results of purification.

[tingdzin]

O.K. true, but I am wondering about the application of the theory by those who practice. Does the ritual practice of Shingon or Vajrayana take as assumed that the practitioner has, for example, already mastered each of the stages in the process through individual practice, or is it possible that, as Zhen Li seems to imply, that the Buddha-activity of Amitabha (or another Buddha) comes into play at some point so that this is not necessary? Or, in either Tibetan or Japanese tradition, does such a mastery imply that when going through the ritual so that each of the stages is compressed in time without loss of meaning (as perhaps in a zip file)?

It is a complicated question, and I don't want to over-analyze it. I am just curious about how practitioners themselves view this point.