"Sparkle wrote
I never quite liked that coaxial ABC idea. Sort of like an airplane with
a high Skyhawk wing on one side of the fuselage, and a low Cherokee wing
on the other side.

As a "symmetry" guy, doesn't that bug you?

Not at all.
It's the first shoe to drop, in the inevitable move toward the Intermeshing
and Interleaving configurations.

Dave J