Personally, I found Part Two more engaging than Part One. Don't get me wrong, both are very good, but Part One takes a considerable amount of time to set up all the parts of the plot, whereas Part Two is nearly all payoff. Still, the whole thing is worth seeing- it's very well directed and designed, and the while Miles, Leonard and (especially) Parker have all received well-deserved praise, the whole ensemble is doing great work on that stage regardless of the size of their roles.
I am a firm believer in serendipity- all the random pieces coming together in one wonderful moment, when suddenly you see what their purpose was all along.