Today I set up my new Ducky Shine 2 TKL Chinese version with red LEDs and Cherry browns. It wobbles with or without the feet extended. I haven't checked to see if the problem is with the rubber pads. Whatever the source of the problem, I fully agree that a supposedly premium keyboard should not wobble. This indicates poor build quality and poor quality control. Otherwise, I like most of the features of the keyboard (except for the feet, which are not rubberized and so the keyboard slides instead of staying firmly put), but my enjoyment of it has been marred by the unfortunate wobble defect.
Edit: I tried replacing the rubber pad with new silicone pads. This lessened the wobble but did not eliminate it. It seems that the case is not even.
My IBM Model M and my Filco Majestouch-2 TKL do not wobble.
BTW, another odd thing about the Ducky is that the uppercase and lowercase legends on the keycaps are reversed. However, there is a certain logic to this. After all, the normal legends on the letter keycaps are uppercase, so showing the legends of symbols that are activated by the shift key on top makes a kind of sense and adds to the whimsical charm of this keyboard.