Gus wanted more money than CBS would give, so he's over in Murdoch-land. I don't miss him in boxing but do miss him in the NCAA Tournament.
Mauro, aside from his weird fake voice and the way he tries to manufacture excitement, is a really good commentator. You can tell he does his homework on the fighters, and he knows his boxing history as far as he needs to. Gus also had an over-the-top delivery, but add to that the fact that he DKSAB and couldn't go through a broadcast without saying something ******ed. Mauro generally has good stuff to say and knows how to interact with the other commentators.