I have two, and cannot see any “rubbish” in their operation - granted, I am not doing live performance with them, but i have not run into any issues with functionality.
I believe kazakore also has one.
Here are some neat vids of really doing some cool stuff with them - Infinte Sinewave
Feel wise, the pads are nicer than the ones on my Akai MPK - 61, not as nice as the ones on my Axiom 25, but that may be personal preference - the pads are nicely thick, have a decent feel - My guess is some of the restriction in feel is due to sharing a piece of silicone with the sliders which of course cannot be sticky, and additionally since the pads are also x-y controllers, it may not work well if they were “softer”.
If you can site references to the rubbishness… I would love to investigate!