I agree with this very much. I would say "choiceless awareness" is another way to describe "open, spacious awareness," open to everything, anything and nothing in particular, in equanimity and without judgement ... one of the key aspects of Shikantaza.
However, the other key aspect of Shikantaza is what you say, "
the sacred act of sitting and the timelessness of that sitting and how when we sit we embody the body of the Buddha and we do this beyond the use of some yardstick to measure." It is precisely this that distinguishes Shikantaza from many flavors of meditation which are subtly goal oriented or "instrumentalist" as tools to get something. It is the very drive to "get get get" that is the source of suffering, and the very dropping of the tools and goals that is "getting the job done." It is so much so, that we like to say that Shikantaza Zazen is not even "meditation" (although it is, a kind of "non-meditation meditation.")
I do not criticize other forms of meditation for those who benefit from those, but the brilliance of Shikantaza is the realization that the true cause of Dukkha, and our separation of our self from all reality, is this need to get, do, find a tool, fix and accomplish, achieve, get somewhere.
In my understanding, Rev. Sokuzan considers himself as much a successor to Trungpa as well as Sokuzan's teacher in the Kobun Chino Lineage, and even the Kobun folks can be a bit grab bag in their approaches. It is lovely, many ways to make the soup. Find the soup right for you.
I like the soup of Shikantaza, for it helps us realize the delicious nature of life's soup, and to become "one with our bowl," because we radically stop looking for the "True Soup" in somebody else's bowl, stop dreaming of some other kitchen, radically stop thinking that we just have to add this or that to make soup into soup, thus to discover the Buddha's old recipe ... and simply taste the richness and nutrition of this Buddha Bowl of Soup which has always been here all along. Then, diner, water, carrots and broth, bowl and breath, air and chair, sky and tongue, spoon and stomach all are just one ...
... YUMMY!
Gassho, J
stlah