analog.matt, not worries, i'm not attacking your preferences. i'm not trying to be overly scientific, nor trying to scrutinize your thoughts.
allow me to explain where i'm coming from:
i said what i said because i wanted to qualify that if the musician wants clean, and not overdriven sounds, tubes and solid state power will have the same loudness output.
use case: there are some applications (Ex: jazz, acoustic) that require a very clean output... much cleaner than the "clean" of a blues/rock player. for these applications, you really need a good amount of clean watts regardless of technology.
i hope this sorts things out. i'm just not a big fan of proclaiming that something is better without qualifying the application.