I 'll add my experience with asyncio and twisted:

1) debugging is way better in asyncio, with ipdb you can step in co-routine. In twisted, you will end up somewhere in internals.

2) asyncio is end of unhanded error in deferred :) (or you need to remember to add addErrback everywhere, even after addColbecks and addBoth)

3) with trial testing is frustrating, sometimes error raised in wrong test because of global event loop (for instance you forgot to mock external call). In asyncio world loop passed explicitly and this is good for testing.