Aful looks smoother to me. The wobbles in the Aful are very low variances and are not audible to me. I haven't heard the Red yet but the resonance peaks are a lot higher, it goes both higher in the peaks and and lower in the dips. I don't think the Red looks enormously problematic or anything and usual caveats about IEC-711 measurements over the insertion resonance but if we are specifically talking about the Aful vs Red treble over 6kHz on "that graph" specifically, the Aful does look smoother in that region, on "that graph". Variations is also smoother, and this is one of the things it is most often compared as an improvement on the Blessing2, it is smoother in the treble. B3 (which I haven't heard) is from accounts also smoother than the B2 in the treble, and there are hints of that in the graphs too.But the Aful has anything but smooth treble in that graph. My question to you was what do you mean by smooth treble. But this discussion is going nowhere so good luck in your search.