I'd read about half the stories in Exhalation before picking up the collection having seen them scattered across the internet over the last 10 years or so, that put me off for a bit but in the event I enjoyed reading it all again.

Anyway, in case you hadn't heard Ted Chiang is really good.

The opening story about a time traveling doorway has heavy Borges vibes and doesn't come off badly from that comparison. The title story is an all time great and reading the notes at the back was a real "aha" moment for me; of course it's a riff on The Electric Ant.  The newest story in the collection, the last, is also one of the strongest, it's a subtle but distinct broadening of his style, the language is looser but without ever losing the careful construction that Chiang is rightly feited for.  (There's only one real dud in here and that's a short one). Repeated themes are: Free will, yes or no? and: The search for meaning in a godless universe. But that’s reductive, there are real characters with genunine humanity in these carefuly constructed thought experiments, and this is all done with imaculate prose and a genuine affection for and mastery of genre. 

Recomended.