I don't know a
Gregory under the age of about 35; most are older. I had a Catholic boyfriend once who was
Gregory more often than
Greg; nice enough person.
Cosmo screams 'glossy magazine', so I'd avoid it. (I'm afraid I've just thought of a sibset:
Cosmo, for that reason, and
Gregory Quintus, who would go by his initials.)
Gregor appeals to me much more than
Gregory, and niftily references Scotland and Germany!