the two issues I have with async is are:

1) its infectious. You need to wrap everything in async or nothing.

2) it has non-obvious program flow.

Even though it is faster in a lot of cases (I had a benchmark off for a web/socket server for multi-threaded vs async with a colleague, and the async was faster.) for me it is a shit to force into a class.

The thing I like about threads is that the flow of data is there and laid out neatly _per thread_, where as to me, async feels like surprise goto. async feels like it accepts a request, and then will at some point at the future either trigger more async, or crap out mixing loads of state from different requests all over the place.

To me it feels like a knotted wool bundle, where as threaded/multi-process feels like a freshly wound bobbin.

Now, this is all viiiiiibes man, so its subjective.