I bought these to reduce the noise from Kailh Box Brown v1 switches. This is success. They are not completely silent, as few non-linear switches are, but well enough for me. Slight "sandiness" might be heard on some switches if it is pressed in an angle instead of directly downwards, but that's not an issue for me, I rather like that sound too.
Another improvement over Brown v1: the actuation point is exactly at the end of the tactile bump, so every time you feel the bump, you can be sure the key was activated. In Brown, the actuation is slightly lower than the end of the bump, so I sometimes missed the keypress if I pressed the key only lightly. The bump feels more tactile and longer in this switch, which is nice.
Overall, exactly what I was looking for. I would need to test other tactile linear switches to make be better informed, but at the moment I'm satisfied.