I'm on mobile so cant type a long response but IME its quite different in terms of ease of use, complexity, and correctness.

For a theoretical take see

https://vorpus.org/blog/notes-on-structured-concurrency-or-g...

To be precise, to wait for a task its actually just await. Theres no ensure_future etc. Trio doesn't have the concept of futures or promises at all, and await f() is treated as a single piece of syntax, so in practice it doesn't have "awaitables" either.