The current state of affairs is somewhat up in the air because Alex Crichton (futures) and Carl Lerche (mio) are working on the Tokio project [0][1], which is likely to become the most favored way to do things on top of mio.
[0] https://github.com/tokio-rs/ [1] https://medium.com/@carllerche/announcing-tokio-df6bb4ddb34
It's still under construction!
Every day something new breaks, haha. Whether it's tokio-middleware with the "what was I thinking?" patch:
https://github.com/tokio-rs/tokio-middleware/commit/78210757...
(seriously, click that link it's funny)
...or today's fun:
https://github.com/tokio-rs/tokio-minihttp/issues/12
The good news though is that it is obviously being worked on--heavily. The Rust ecosystem is so new that it feels a bit like we're in the Wild West. Someone comes up with a decent way to do something and then after a bit of ecosystem evolution we're back to the drawing board since, "there's a better way."
This is all very good because it means that the Rust ecosystem is evolving rapidly. It also means that developers are productive enough in the language that entire frameworks can be re-written from scratch in a reasonably short amount of time. I think it's a good demonstration of how effective the language is overall at its goal of improving productivity (as far as systems programming languages go).
With tokio I could unify my code base and make the code simpler and easier to follow.
This is pretty normal for an ecosystem at Rust's stage of development. Ecosystem development is always something of a monkeys-on-typewriters effect and if you continuously have major disruptions in the language, you wind up with Javascript Fatigue.
What I'm particularly impressed with in Rust is the core team's leadership. I'm looking forward to Tokio because I think it's likely to have Rails-like dominance over the ecosystem. This is exciting because it gets us monkeys all pointed in the same direction instead of writing another postgresql client because existing ones don't support the current flavor of event loop that I'm using. Getting to the point where we can snap a bunch of pieces together and have a network service is huge for office advocacy. I think it was a key factor in Ruby's wins over the more established Python web community when observing from the Python side.
I'm also pleased that the Rust core team is focused on my pet areas of improvement: editor support, impl Trait, and async network services.
There are also some "Are we X yet?" sites that cover ecosystem maturity for specific topics. Here are all the Rust-specific sites linked from Mozilla's page (https://wiki.mozilla.org/Areweyet):
Web Programming - http://www.arewewebyet.org/
Concurrency - http://areweconcurrentyet.com/
IDE/Editor Support - https://areweideyet.com/
Machine Learning - http://www.arewelearningyet.com/
Game Development - http://arewegameyet.com/