[jnwatson]

There are two general issues here: there's the nuts and bolts, and then there's the emergent properties of the protocol.

In my experience, async (which includes futures/promises, and actor-like mechanisms) makes the nut-and-bolts problems of avoiding variable race conditions, avoiding deadlock, managing multiple things going on, way easier.

You still need fuzzing and model checking to make sure you got the strategic stuff right.

That said, the team I work on is about to release our first Raft-based product, so I might have a different opinion in a few months.