Class aB solid-state has such a large range of primary currents that I consider thermistors unsuitable. True Class A solid-state and tube amps are a different story.
I like relays as well, but the triacs (thyristors) are sooo much easier, and the dozen or so units that I've installed them into work like a champ.
I like relays as well, but the triacs (thyristors) are sooo much easier, and the dozen or so units that I've installed them into work like a champ.