Yea If a Mountain bike racer, not a JRA old person, you would dislike them..
My 20" wheel BiFri, 160 disc BB7 had virtually no front modulation
(disc being 1/3 of the wheel size, may have some influence.. )
at slow speeds approaching a blind corner
with a building tight up to the sidewalk, Car right in front of me,
It Stopped the bike, but my body did not..
I thought about using one, Instead bought TRP Hy Rd Calipers,
so am finding, they have a smoother modulation..
With adjustable cable pull MA Avid Speed Dial Levers , I have more adjustments
to get the feel right for Me.
[Yea Disc Vs V is apples and Oranges ]
...