Bartokfan, the assumptions you make pertaining to the characteristics of tube are incorrect. There are a great deal of variance is sound characteristics of any given tube from different manufacturers. A Tungsol 6550 sound very different to an Electra Harmonic 6550, which in turn sound different to SED, Svetlana or Phillips 6550s.
Additionally, factors such as the circuit design, quality of components, screen grid bias method etc. etc. have dramatic effect on the sound.
EL34 are generally known to be very melodic when run in triode mode, yet partnered with the right speakers they produces a prodigious bass slam in my V12i. KT88s are known to have bass slam, but they are wonderfully melodic and detailed in my Audionote.
Observations on what a amplifier/tube sounds like, should be made after auditioning, not before.
Regards
Paul