Herman,
I did get to listen to a pair of 20.6s at my dealer's that just came back from a Levinson refurb. They got better over a period of 72 hours of re-break-in and they did sound very good, but still recognizable as 20.5/20.6s. I can't say that they sounded better than before the refurb (Levinson refused to say that also by the way), but they certainly did not sound worse.
The Lamms are a 2004 or 2005 design and are Vladimir Lamm's reference state-of-the-art best that he knows how to design and build. Listening verifies that our best high end audio engineers have not stood still these past 16 years. They have actually found ways to improve their products. Also, some of us believe the tubes in the hybrid design do make the length and decay of notes more realistic while the solid state devices make the attack of the notes more realistic.
Lastly, it was not a question of finding something I like. It was a question of finding something I like even better than my 20.5s
Best,
Ed