Class A Watts

My earlier XA100.5 monoblock's from Pass were superior in drive and dynamics compared to my modified Nu-Vista 300 poweramp from Musical fidelity which gave more than 2 times 350 watt by 8 ohm.

I own a Sugden A21SE and at only 30 wpc Class A it does not play louder than other well designed 30 wpc gear, but it is definitely quicker and approaches that oft elusive tube sound. The characteristics of speed, solid bass response and openness of vocals.

If your speakers are low impedance, or have an impedance curve that varies quite a bit, both current delivery and output impedance of the amp (damping factor)will have a greater effect on the sound than the amount of watts that the amp puts out.

However, there are A/B amps with no switching distortion and much quicker than lots of class A amps. Just because it's class A doesn't mean it's better than any other topology. Conceptually, it is ideal with regards to this issue. As far as tubes go, you're not going to get there without mosfets in an ss amp.

Going class A is a method of reducing distortion. In a high end amplifier that is supposed to sound like music, this can really help in a lot of cases.

Class A is not the defining criteria though. There are all kinds of design considerations that affect the way an amplifier can sound.