I think the two new books definitely give a much richer and more interesting account of Archipelagan society, and also historical perspective. Ah, I want to start giving reasons why now, but no spoilers, of course!

I'll just say that if you do decide to take the plunge with them, make sure you read the short stories in order - I did my usual trick with short story collections of shifting around the book, but they are meant to be read in sequence.