According to Jimmy, asyncio.get_event_loop() behaves differently if it's called while an event loop is running. So my first benchmark was wrong.

Attached bench_get_event_loop.py measures asyncio.get_event_loop() performance when an event loop is running. I get a different result: 

haypo@selma$ ./python -m perf compare_to ref.json patch.json 
Mean +- std dev: [ref] 555 ns +- 11 ns -> [patch] 498 ns +- 11 ns: 1.11x faster (-10%)

Ok, now it's 10% faster :-)