FWIW I was mostly on the compliance side, so didn't have all that much direct exposure to the transaction side of things. But from the exposure I did have, I didn't see a huge difference. A transaction is a transaction. And the transactions were at the DB layer, so I wouldn't think the atomicity primitives built into the Clojure language would be all that useful.

Like anything, the middle tier should be largely stateless anyway, so using Clojure atomicity primitives in business logic may even be an anti-pattern.