Booker is perfectly fine as a GM for me as he's got presence, mic skills and he can be a credible authority figure in whatever position they wanna put him in the middle of.
AJ, I can't stand. She was fine as the sidekick to Bryan but the more spotlight she got throughout the Punk/Bryan/Kane saga, the more irritating and one dimensional she got. I can understand they wanted to do something with her because she was pretty over, but picking her to be GM was a terrible choice. The skipping is annoying, the retarded head tilting is just as annoying and her mic work is nothing to write home about. I just can't taker her seriously at all, at least Johnny was entertaining because of how awfully awkward he was and constantly flubbing his lines no matter how much I hated him too.
In conclusion, keep Booker and fire AJ and replace her with Flair.