The unfortunate bit is you lose out on so much of the ecosystem going hard on asyncio right now though (like sqlalchemy orm).

aiohttp + pee wee async is the best combination available right now IMO. A fully asyncio app with pleasant non-blocking ORM and migrations.

I'll have to give that a shot sometime. :) Haven't used peewee before, as sqlalchemy has mostly been tremendous.

That said, if I'm starting a new project where I'm pretty sure I need async io, I'm not sure Python is my first choice. It's got decent facilities but compared to other ecosystems it's not as mature there

Quart is another option. Even more of a "drop-in replacement" than sanic.