+1 My point above (using the Shuttle as an example) is that every amp sounds different. The Shuttle is a good example of an amp that is 'tight and bright' . The low end voicing, along with the design and starting point of the bass shelving control, results in those amps punching down low and sounding very articulate up top (love it... even the big, full weight 1200 has a bit of this inherent voicing to my ear... has nothing to do with 'class of amp' or whatever). However, if someone is looking for massive low end extension, that amp would not be one I would recommend. Others do that better (some class D, some class A/B, some class G!).
My main point is that every amp has its own tonal profile. For some reason, those who try a micro amp that they don't like seem to quickly attribute what they don't like to the class of amp, or the size of the unit, or whatever. You rarely hear those who try a
Thunderfunk550 (which has a similar punchy and somewhat attenuated low end) say, 'I tried a class A/B amp with a transformer and they sound thin down low'
Lots of different voicings in all these amps (tube, small, large, whatever). That is mostly due to the 'sound in the designers head', and is primarily influenced by the preamp voicing, the EQ center, Q and shelving start points, the hi passing and additional low end voicing, and the power management design that kicks in as you push the amp.