In the whole gamete of ontological arguments put forth through history, nobody has ever been able to explain why the thing that violates infinite regression must be some sort of "omnimax infinite". And Davo is right, existence isn't a quality. First of all, to label existence a quality would mean that to not exist is also a quality, and a thing that doesn't exist cannot have qualities. It is through the act of existence that a thing can be DEFINED by its qualities.