Tube amps have a signature sound

Hi folks, this is a bit controversial issue. We all know that nowadays none of the tube amps exhibits the "typical tube sound" (what is the typical tube sound anyway?). If someone says: tube amps have a signature sound, others would say that this signature sound is not typical to tube amps. Well, imho there is something with many tube amps (pre and poweramps). They sound quite fluid, especially in the midrange. The midrange itself is often a bit bigger and more forward than the typical solid state amplifiers. This midrange has also a certain "natural" quality (harmonic richness?). Of course there are tube amps that sound like solid state and solid state amps that sound like tube amps, but in the end I have to admit that many (or most) tube pre and poweramps have a "signature" sound that is somehow related to implementation of tubes in the circuitry. I think that this is also the reason why some manufacturers prefer tube over solid state circuitries. What do you think?

Chris