I am quite convinced that tube power amps need a clean sounding SS pre like Soulution, possibly CH or Dartzeel or spectral, when used on cones. They will also add to separation and drive and take out the muddiness. Micro will benefit on his Wilson with both lamm and VTL using this strategy.
I have tried it with Dartzeel, Krell KRC (a great preamplifier) , Cello and even an old Spectral. Still prefer a matching tube preamplfier with a tube power amplifier. BTW, the Lamm L2ref preamplifier is a solid state and the tube LL1 preamplfier sounds much better with any of the Lamm power amplifiers I still own.
Just to say that there is diversity enough whitin the SS and tube to rule out dogmatic laws. My personnel choices also reflect my preference for the DCS Vivaldi stack and the music I listen.