Some time ago I finished my re-listen of the Discworld books’ City Watch subseries with Night Watch, narrated by Stephen Briggs. When I first read this, I didn’t think the time-travel sections had a coherent plot. Audio helped me pay better attention to the narrative flow and understand the way the two versions of the past were in tension. Time-travel plots still make my head hurt, but at least now I comprehend the past events.
It strikes me that this and Thud! are the culmination of the books about Vimes, in the same way that Lord and Ladies and Carpe Jugulum are the culmination of the books about Granny Weatherwax. (I was going to say that Thud! was superfluous, but it contains Vimes as a father.) Unless something highly unexpected happens in Ankh-Morpork, I predict that Vimes will be a supporting character at most in subsequent Discworld books.