I've been using Django for the last 10+ years, its ORM is good-ish. At some point there was a trend to use sqlalchemy instead but it was not worth the effort. The Manager interface is also quite confusing at first. What I find really great is the migration tool.
Since Django has gained mature native migrations there is a lot less point to using SQLAlchemy in a Django project, though SQLAlchemy is undeniably the superior and far more capable ORM. That should be unsurprising though - sqlalchemy is more code than the entire django package, and sqlalchemy + alembic is roughly five times as many LOC as django.db, and both are similar "density" code.