I have VTAF installed on my VPI Scout, with an Origin Live OL1 tonearn, VTAF is nice, because you can adjust it while you are playing, and you can really hear the difference.
One point, is that VTAF is audible when you have a contact line stylus. If you have an elliptical stylus, you are not likely to hear much of a difference. With my contoured contact line, I can hear the difference when it is off. So I simply get up and adjust it while playing. A few minutes ago, I was playing and old Sheffield Lab LP, Harry James "The King James Version." I did not like the sound of Harry's trumpet, so I got and turned the VTAF adjustment about 1/2 a turn, and Voila the sound was great.
So this is a great tool an Audio Techno Bigot.