I have found that my tube and solid state amps and pre-amps need about 30 minutes to sound their best. (to me).
I turn the system on when I know I'm going to listen and go do something else for awhile.
Also, my preference is a tube pre-amp over a solid state pre-amp and a tube or solid state amp. However, this totally depends on the equipment auditioned.
If one was given the top 5 pre-amps (5 solid state and 5 tube) and top 5 power amps (5 solid state and 5 tube) in a particular price point range that could correctly power your specific pair of speakers, I would bet that you would be a very happy camper and you would have no problem going back and forth between equipment, regardless of whether it was tube or solid state.
But, back to the point, warming up equipment is really necessary to perform their best. Anyone telling you otherwise is trying to sell you something.
Don't let the oil get to temperature and flow correctly in your car and you will find that you will need mechanical work sooner than if you did let it warm up.
My system sounds cold (I know, not a great description), when not warmed up. But, when it warms up, it really opens up. Solid state and tube. no difference.
enjoy