The knobs don't pop out, the face around them retracts - Servo-Face. Gimmicky, I thought at the time; store I worked in sold them. What I didn't like about them was the wobbly feel of the pots, which had long shafts and several of us felt that would contribute to a failure of the pots because the user had a lot of leverage on them due to the looseness of the design. However, if it sounds good and the pots aren't noisy, then maybe go for it if you like it. Me, not so much, but that's why there's chocolate and vanilla and lots of other flavors.