It looks like these tinny things can not drastically effect your playing. But man, it's so annoying when your knob is loose and when it's turning around the potentiometer shaft.
German engineering is famous worldwide, and it's not any different when it comes to Warwick products. This thing is so precise, and it grips excellent with your hands.
It has a screw which helps it stay on the pot shaft, and as I noticed, the screw is little bigger then on the other knobs, so you would need a bigger allen key (2mm). The mark, which happens to be a whole, can be convenient when you want to know where you are with your volume/tone.
Also, it doesn't fit on some thicker pot shafts without teeth. But it fits perfectly on regular pots you find on most guitars and basses.
I would highly recommend it!