Musicdre - words of wisdom. And, your list doesn't include the often troubling spitting, hissing, etc., of one tube just not wanting to play nice with the other tubes in the sandbox. And, not that it's a sonic issue but the ridiculous inefficiency of tube amps is bothersome to me. But, more importantly, as I've noted, GanFets now seem to be closing the gap to glorious, "burnished" tube sound such that it becomes ever more difficult to justify the wastefulness associated with tube gear and this coming from a dyed-in-the-wool tube guy for at least the last 30 years. Consider this quote from Michal Jurewicz (head engineer at, and founder of, Mytek) when discussing the need for faster Mosfets,
"...but it's not yet 100% what could be accomplished. For a better squarewave you need power transistors called GaN-Fets. It's a game changer for class D. In the next few years we will see examples of class D proving to be the best sounding amplifier technology with the use GaN-Fets..." (Stereophile, May, 2021, Vol.44, No.5)
Far as I'm concerned, we're already there. Note the descriptors used by those on this thread who actually tried a GanFet product albeit not mono's and maybe not XLR. Using monos and XLR to take best advantage of the kit may not provide the pleasurable distortion spectra of tubes but, well, the little 5 lb.., 300 watt, MiniGans continue to sit atop the 100 lb., 845 mono space heaters, figuratively and literally, which have remained silent since I started listening to the MiniGans.