I'm really impressed with this passive controller. The build quality is excellent, it feels sturdy, and it doesn't introduce any noise or distortion that I can discern. The gain knob feels smooth and even across its entire range, and the switches don't add any pops when toggled.
I paired this unit with M-Audio BX5's which have inaccessible volume controls on the rear, and a Zoom H6 which acts as my audio interface, neither of which gave me the instant control I needed. Its a really well put together basic unit if like me you didn't need anything fancy, and the price really reflects this.
The only minor grievance I have is that the indicator on the main control knob is on the side - and because the unit is slightly sloped it is often difficult to determine its position from the 9 to 3 o'clock position. I remedied this by simply adding a mark to the top of the knob so I could see it in all positions.