Be wary of compatibility! First of all, QMX-Clips don't work with plates.
Both types of clips (QMX-Clips and Zealencios) are designed for keycaps in Cherry profile with switches oriented with the LED-window facing south.
They are not compatible with thick Cherry keycaps on switches with the LED-window north (Cherry logo upside down) because of the thickness of the bracket. This rules out thick keycaps on a great many keyboards, including almost every one with backlighting.
They are not compatible with clicky Cherry MX, Greetech (some Razer) switches because those have sliders with a small protrusion that gets in the way. Clicky Gateron switches work.
Kailh-made switches (some Razer) don't work because those have different housings.
They were made for Cherry profile with the struts it has inside the keycap being relatively close to the switch housing. OEM-profile would need a additional thin O-ring of some kind. SA, DCS and maybe also DSA profiles are unsuitable because they don't have any struts (in every key) and at the very least you would need to place a stack of O-rings inside each keycap to get any effect.
But if they work for you, then they are great!
BTW. The QMX-clips are available also on Uniqey's web site and could ship faster from there.
However, they don't ship to every country: only German-speaking countries, UK, USA and Canada. And only in Germany would it be cheaper to buy a pack from Uniqey directly instead of going through Massdrop.
(I got mine through a proxy. If my proxy read this, Thanks Again!)