How do the Merlin TSM compare to other speakers

Sorry to hear about your loss, Bobby. Hope that your wife & you find the strength to cope with it.

I'm not a Merlin owner but I feel that I own a speaker that has a similar signature to the Merlin & possibly uses the same or similar tweeter.

With a high Q speaker, a high damping factor power amp is not needed - I can see this. However, why does it hurt to have a high damping factor power amp driving the Merlins? Electrically, the lower the o/p impedance of a voltage source (power amp) the better (as it tends towards ideal). The lower the sum of amp o/p impedance + speaker wire impedance, the better the bass response should be.

Ach! Intuitively I can see (perhaps) what might be going on: high Q speaker + high damping factor power amp => too much of a good thing in that the amp is great at controlling the woofer that has already been damped by the speaker cabinet. So, I can see how this reduces the bass - the woofer excursion is curtailed very quickly by the low impedance of the amp.
By having a higher o/p impedance in the power amp, only the speaker cabinet controls the woofer excursion as the power amp is "sloppier" in this dept.

No wonder then that the Berning ZH270 sounds best w/ the Merlins w/ its feedback at the "low" setting, which creates a higher o/p impedance & a lower damping factor vs. the other 2 settings.