Speakers known for great midrange.

Not a stand mount, far from it...Duntech Princess; excellent midrange.

Jose.

The original QUAD ESL is considered the standard for midrange reproduction, but does not sound syrupy; for years it was also the standard for transparency. For smooth and somewhat soft sound (a mild form of syrupy?), how about one of the old Vandersteen's (the Model 2 is a favorite)?

Tekton, LOL that's mid price stuff at best and they're ugly as sin.

"I hear the Harbeth quality control can be hit or miss."

And where did you hear that from? Do tell!

Sorry.  If great midrange is your priority, you need panels/electrostatics.

Could put them on stands I suppose.