Any one tried king stax cones?

Hey everyone, has anyone tried the new King Stax from King Kone? They’re designed to load 169 cones at once (or 100 for the Knockbox), but the 109mm size is constantly sold out, which makes me think they’re actually decent. I’m considering grabbing some ‘Dog Walkers’ to test out, but I’m a little skeptical about that plastic loader—it looks like it might be a bit finicky. Anyone here have hands-on experience with them yet?