Whether a designer takes advantage of this fact is another matter but generally speaking GaNFET amps should sound better as they have less distortion on that account.
@atmasphere
As you are well aware, I’m kind of touching on an issue of specmanship that that affects us with all amps. Can we hear "better" when you go from 0.01% distortion to 0.001%? I know distortion can be reduced, which technically means more fidelity to the input signal. What I don’t know is that this alone is audibility, let alone desirable.
Like Tube amps, or Pass (who makes it clear this is his goal) the distortion profile may have more to do with euphonic capability than merely lower distortion.