I can't really add anything since I'm not a philosophy buff, but I can note that this is one of the more interesting theological debates I've read on here to date. Thanks, guys!
Anyway, I'd say that as a philosophical argument, it fails to regard the naturalist fallacy (I hope this is the universal name for it), in that it relies on
theory (i.e. God is perfect because that is most desirable -- which it may very well not be), to base an argument. In essence, it's using a theory that can't discriminately be disproved to prove another point.
This is a terribly constructed thought, so I will simplify.
"Man cannot see Planet X without optical aids."
You can't disprove that, so it must be correct. In essence, this is exactly what I see the Ontological Argument doing in terms of Divine Existence.
Blah. I hope after a 9-hour workday this makes a shred of sense.