I think Mosley was clearly, at his prime, far superior to Andre Berto; at least based on what I've seen. So, the question is really just how much of Mosley's prime assests - mainly his speed- are with him at this stage.
I'm rooting for Mosley, and I think Berto might have shown he's past his level of comfort during his handler's steady ascension of their prospect; Berto is in over his head.