"tube watts" versus "solid state watts"


I'm sure you, like me, have seen it written more than once that brand X tube amplifier, rated at 30WPC, sounded more powerful / more authoritative than brand Y solid state amplifier, also rated at 30WPC. Or that brand Z tube amp, only rated at 15W, was comfortably able to drive brand A speakers, because those 15 were tube watts and therefore up to the job. Heck, I think I've even heard the phenomenon with my own ears.

My question is: is there any basis in electrical engineering for this effect? Can we say scientifically what's going on here?
128x128twoleftears
Distortion usually increases with demand. More Watts = less clipping. Having more Watts, lessens the chances for distortion. On a cost per Watt basis, ss usually offers more Watts for yer dollar than tubes. One could argue that avoiding distortion is preferable to accepting more pleasing distortion. While it's an old fashion notion, and certainly not the end all towards choosing an amplifier, perhaps we should re-consider $ss to $tube Watts as part of this discussion.
To me,most tube amps seem to sound like they have more power than a SS with equal power.Also if I remember right,tube amps have even order distortion vs. odd order distortion put out by SS amps.This may already have been mentioned.
I think it has to do with the tubes warming up the hair in your ear. The vibrations of the ossicular chain displace the basilar fluid in the cochlear, causing the hairs within it, called Stereocilia, to vibrate. Hairs line the cochlear from base to apex, and the part stimulated and the intensity of stimulation gives an indication of the nature of the sound. Information gathered from the hair cells is sent via the auditory nerve for processing in the brain. That's why men love tubes.
It's not a tube vs transistor issue. I've had numerous amps all rated for 100W both tube and SS. Some sounded like kilowatts, some sounded like milliwatts. Some were just not a good match for certain speakers. Just trade-offs in the design/price. I could be more specific with the individual models but that would serve little purpose and be misconstrued as criticism.