Never used one but I’ll go ahead and give my worthless opinion. The only footprint they make currently is for the Sig Romeo 1 which no one uses and even Sig is going to give up on. So even if you wanted it, you can’t put it on most pistols. You might be able to buy an adapter plate but why would you buy a plate that limits you to at best a junk dot (R1) and a questionable dot (grace) when you can just get an RMR plate and have your pick of many good dots?
Then there’s the issue of shooting correctly with both eyes open, which is how you are supposed to use a red dot, which negates their entire “topless” gimmick.
So, too dumb to use a popular/usable footprint and built on ignorance of the fundamentals of usage. That doesn’t inspire much confidence.