I haven't followed the politics behind ADM, but for whatever reason, I do remember the initial Mark Larue review of the ADM offerings, where as I recall, he really couldn't say anything bad about them.
I don't see any particular similarities between the rings (again, that doesn't exist elsewhere), or the Lever Lock system, unless that it contains a lever, and a lock. I think is that the design is superior to the Larue QR in ease of adjustability, attachment, and unlocking/detachment. It is easier to mount to a larger variety of rails (with no tools), holds tight, is easy to unlock, and does not mar the rifles finish.
I can say, we can put them on other peoples guns without marring their finish, which I couldn't say about the Larue mounts.
ADM for the win.
I reckon if Larue mounts were easily attainable in Canada and ADM was restricted because the manufacturer couldn't bother to fill sizable Canadian dealer orders, people would be screaming out for ADM products.
Either certainly work fine to accurately hold a scope to a rifle.
DT