I have actually read Atwill's book. It's in my library now if anyone needs access to any page. I find it...hysterical and easily refuted, to say the least.
Among about a thousand things Atwill has no answer to:
Paul. There is general agreement among scholars that the first of his letters was written in the early to mid fifties. Long before Vespasian.
Besides, the idea that the Romans created a cult that they kept trying to exterminate is simply laughable.
Have a great day, JOhn