Tube Watts vs. Solid State Watts - Any credence?

High end audio is definitely tricky. For example, I'm running a Primaluna Dialogue HP Integrated Amp with EL34 tubes to Sonus Faber Olympica III Speakers which are 91db efficient and are 4ohms rated according to specs. The Primaluna has 4ohm taps and 8ohm taps, and the 4ohm speakers sound far better on the 8ohm taps.

I don't remember where but once I read that someone was comparing the sound of 100 wt Gryphon with 600 wt Krell, both transistor amps. Same speakers,forgot what that was. Besides sounding a lot better in every respect, Gryphon also sounded more powerful. Dynamic speakers, this I remember.
What are the possible explanations?

Uh - a watt is a watt ...it is a unit of measure there is no difference by virtue of the device that produces it.

Now frequency characteristics, load interactions and clipping or distortion characteristics- that is different.

A practical question out of all of this is power tube choice in the same amp. Currently am running eight EL34's tubes in a primaluna HP integrated amp to Sonus Faber Olympica III speakers. The Sonus Fabers are 91db, 4 ohms, and recommended amplification of 50-300 watts.

Tube choices in the amp are as follows:

ULTRALINEAR MODE:
85 watts x 2 (KT120)
73 watts x 2 (KT88)
70 watts x 2 (EL34)

TRIODE MODE:
45 watts (KT120)
42 watts (KT88)
40 watts (EL34)

I know tubes have there own characteristics, but besides that, from a power standpoint, would it be better to go to KT120s to get more power to my speakers? Would the difference in wattage moving from EL34s to KT120s (15 watts increase in ultra linear, 5 watt increase in triode), be beneficial or even perceptible to my ears? Would this be better for the performance of the speaker, or at least the health of the speaker?

Wow thats a tough one i was up all night thinking about that!!