Quicksilver v4 monos vs CODA Continuum No. 8 Version 1.

Class A amps don't transition to any other class. They run at full power all the time.

Class A/B run in class A until the signal is high enough to transition to class B.

The class A to A/B transition feature is mostly just marketing.

What are the speakers you will be using?

I owned 2 of these Duo XD amps before and liked them more than the #8.

I’m pretty sure that Krell Duo 300XD is good sounding amp, but unfortunately I have some bias for vent cooling concept. Probably sounds paranoid, but the idea of some moving parts inside the amp kind a disturbing to me.