Compared to . . .
…..as an absolut term.
But MoFo seems to have the mid tones like a 300B but with more bas control. I felt a deeper bas in the room compared to ACA. I use the track "Drums stop no good" with Steve Smith to test that (do you know that track?). I have some reference tracks I listen to when I have new equipment to listen to. I think the "Drums stop no good" it very good to test the power of an amp in the low end. Also some pipe organ tracks played on large organs is a good test for bas response.
Mid and high tones compared to ACA my subjective feel is that ACA sounds a bit on the "hard" side compared to MoFo. But still ACA sounds very good.
I have to listen to MoFo long time to be sure that what I heard first time is also the conclusion after long time. But that I could listen for hours is a good sign.