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masi61 thanks for the very instructive response. The mention of Greg LeMonde's book is nice. I will check it out. I think the simple rule of .883 x the inseam + the idea of a "square" frame as a baseline, which may not be what everyone wants is an interesting place to start from.
You said that you began to realize that you liked a smaller frame. Did you mean smaller in the sense of still "square" and so smaller in both the top tube and the seat tube, or did you mean not following Le Monde's preference for longer top tubes? Is the overall effect of the smaller sizing to sacrifice comfort for power/leverage?