Guy in my unit works for them. He likes it well enough, but that's all I've got for you.
I forget which is which, but G4 is a subsidiarity of Wackenhut security....or vice versa. Anyways, one is U.S. owned and the other is not. Having the U.S. owned branch allows them to get D.O.T/D.O.D./D.O.E./ etc contracts.
I'm sure someone can speak more intelligently on it, but that's what little I know.