Interesting question. I recommend doing this. Put the toggle in one position... tube or solid state. Forget about your system. Listen to music (not the system) for a couple of weeks. Then flip the switch. Don’t sit down to see if you can hear a difference... just listen to music for a couple weeks. Then flip back.
If musical presentation is generally similar, it can be difficult to instantly tell the difference when doing an A/B. But long term, in music, it can be profound. I look at it like this... let’s say that a system can produce 100,000 different sounds (it’s in the millions I am sure). In listening for a minute you are only going to hear, say, 100 sounds... and your minds eye may be only focused on a few of those... say the drum and guitar. But long term you are exposed to thousands of sounds and the gestalt. There can be big and profound differences.