I have used KeyMo the most and it always stayed put for me. But I know guys who swear by Xeno because it's easy to use. For me, it's all about how well it locks up every time and how it deals with gunk over time
I've also had the most reliable lockup with KeyMo. It's not the lightest, but it feels really secure. I've seen ASR get carbon locked way more often. Xeno looks good though because it's so straightforward.
Tried a few and finally stuck with what’s been steady over time. The ones that lock up tight and come off clean even after heating up are the real deal.