All async systems have pitfalls, I'd say core.async's are pretty minor compared to most other systems. You're right that `go` can encourage bloated functions and it would be better if it, for example, handled exception propagation (I would guess every serious core.async user has written their own go-but-with-exception-handing macro, it's not hard but it is unfortunate duplication of effort).

(I've never had to think about the state machine code when debugging and I've done a lot of core async debugging. That part really does seem to just work.)