Who uses Manny without Gates...that's just silly.
People who use him in a magicians defense that has no other kings of Judah... which means that he's not always used with King Amon.
But yeah, Egyptian Magicians is much better IMO. He's got better initiative, especially with a potential play/add to battle ability, he's got the Invoking Terror cycle, and when paired with Spirit of Temptation he can do wonders. I'm also partly biased, however, because I'm a T2 player and I think Egyptian Magicians is most definitely better in T2 but Manny may have a better shot in T1.