IIRC, the UD 2.0 is an updated and modified version of BodyOpus, where Lyle McDonald adjusted workouts and dietary plans from the original in ways that he believes are more effective. It is cyclical in nature, but not specifically for the purposes of getting into ketosis. It's more of a depletion workouts while eating low carb, then refeed and hitting the gym hard. Lyle warns that it's not an easy diet and that it's really only for males at 12-15% and women at 21-24% bf already.
While I'm fuzzy on recalling the details, I've read all three books, and in many ways they are similar in their cyclical nature. The differences are in diet and recommended workouts. I'm sure other people can provide better information than I, but I will point you to Lyle McDonald's site. If you haven't been there before, it's got lots of interesting info.