Warm vs Revealing—the struggle for balance

Amps that can run multiple types of output tubes are, by design, compromises.  They don't optimize signal transfer of any output device,  so all possible output devices are not optimized with respect to signal transfer in their operation.  For some this is OK, even desirable, for others it's not either.  For those in the latter category, the sane course od action is choosing speakers based on their signal transfer and then having amplifier(s) built that optimize the output devices' transparency and are then tuned for the desired degree of warmth (i.e. distortion, which should be minimal if amplifier + output devices are well optimized) by choice of  coupling capacitors...in this way both revealing and warm can be had

I think, you are headed in the wrong direction. You don't really want to find warmth/detail balance, you want to find the sound that is as close to the reality as possible. Then you fine tune, including with tubes. 

I agree with tomcy6,  get the speakers that you like a lot and bring the best out of them. It will not be inexpensive.

For example, I currently use 4 different pairs of stereo speakers, several amps, sources (essentially multiple rigs), a multichannel rig, etc in 2 rooms. It covers the different flavors, signatures, etc with different types of music that I enjoy (while my moods fluctuate).

1 in 1 out when it comes to equipment/rigs is not a good idea at all (as you're noticing)....

Apparently,  "it is a common problem that many struggle with", as indicated by one commenter. So, let us probe a bit deeper into the psychological make up of many typical dudes. Stop telling yourself that the one sht you got is the greatest sht on earth somehow (because you paid for it and you are somehow the most intelligent dude that ever lived n all). Admit to yourself/acknowledge the strengths and weaknesses of the sht you own (weaknesses exist in all kinds of cost no object gear too). Don't be a feral fan boy of one brand, etc i.e don't put all your eggs in 1 basket. Keep an open mind and keep some options open. 

Everyone that posts on Audiogon has the same situation as you....even if they don’t admit it. That’s the nature of this hobby..That’s why we’re Here.....Every time I get my system sounding Perfect....I’m online the next day looking to "make it better"..Trying to make it "more" perfect......Audiophiles may say they’ve found "audio Nirvana".....but they are really only lying to themselves....That’s why this is such a Fun hobby and such a "frustrating " one at the same time....I love it!!!!...We all love it !!!

Respectfully, speakers make a bigger difference in the final “color” of home audio than any signal component. They sit at the end of the chain and actually create the sound waves you hear. Peter Comeau is my sonic reproduction guru and his big baffle work for IAD’s Brit brands is music to my ears, literally.

With some great advice from the discussions here on vintage pro audio gain, cabling, DAC specs and WiFi streaming - my AE Techron serviced Crown PS 200 drives Wharfedale 85th Anniversary Heritage Lintons and a speaker level output REL T5i with non fatiguing perfection :)

Long story short (too late, right) I found that the pursuit of listening pleasure can reach an actual end point in signal resolution if you like and understand your speakers. It’s all about moving air when things are said and done.