In my H's case, the "awakening" came after he'd been in Replay for almost 2 years. I became very upset about his increasing contact with his EA partner, and for the first time he was able to "hear" me, to admit that he'd felt terrible guilt about the secret meetings, etc, and that they were more than "just friends."
It was as though he was suddenly able to access a part of his brain that had been suppressed for years. However, some days he'd feel as though he wanted to get closer to me and end the EA, and other days the fogged-out part of his brain would be in control ("What exactly is wrong with my friendship anyway?"). He'd quite abruptly switch from one way of thinking to another. He began to want to confide in me again, and to have sex (it wasn't like ML), but everything was still almost completely from his perspective.
After this Awakening he broke up with his EA, which precipitated a deep depression and withdrawal from me and the children. He secretly resumed their relationship. He wrestled with whether he should leave us and move to her city. He also started to have many dreams every night, may of which indicated he was starting to work on his childhood issues. He cycled more and more rapidly, sometimes starting to walk towards me for a hug and changing his mind before he had taken 3 steps.
We began counselling when he decided he would never be able to regain his love for me now that he'd met another. After an initial meeting, the counsellor worked exclusively with him for several months, teaching him how to access his "mature" brain rather than his teenaged one. Very, very slowly, he began to become more human and less alien, though it was about 7 1/2 months from the awakening until he decided to work on our marriage and end the EA. Even then, it was another 7 months until he stopped mourning her loss in his life, and another half a year or more before he was able to process what he'd done and accept responsibility for it--and, more importantly, to forgive himself.
So, yes, as you probably suspected, it was a very slow process. Yet I believe it needed to be, to make all the changes effective. And, of course, the process probably looks a bit different for each person.
I'd be interested in hearing about more "awakening" moments. HB positions the awakening during the end of Replay, which must mean that the LBS is rarely privy to much information about it, however.
