Has anyone in this thread addressed preamp-power amp electrical compatibility? This interface is also important, like the power-amp/speaker interface. Solid state amps tend to have lower input and output impedances than tubed units. Your preamp's output impedance should be at least 10 times lower than the input impedance it sees in the power amp. Other things being equal, this would favor a transistor preamp into a tube power amp, unless the tube preamp's designer has taken steps to lower the output impedance to where it will work with the lower input impedance of a solid state power amp. There are many exceptions. I have one ss power amp with a 100k input which is similar to a tube amp I have. Check your specifications, people. You need to have good electrical matches between all components before assessing sound quality or comparing "tube" vs. transistor sound.
If I'm looking for "Tube Sound", why would I put a Tube Pre in front of a SS amp?
I'm purposefully not specifying speakers as I would like to know in general terms the arguments for and against. So, to the degree that speaker characteristics could also influence the choice, please explain. FWIW, I do not know a phase angle from an impedance curve so I will try and educate myself as we go along. Hopefully, others may benefit too.