Prof,
Very interesting evaluation. My thoughts on the 2.7 as compared to previous models was that is was "smoother and more lush" as you say about the 3.7 in comparison.
This is good stuff....I am appreciating your evaluation as are all reading this. (Who has this opportunity in their home!)
I still think, that it would be beneficial to compare the tilt of the 3.7 and try to match the same on your 2.7. it may give you a different impression, but maybe not - as I recall you were nearfield in you listening position.