It's slow as hell. And every version bump comes with a bunch of new warnings/errors by default that is quite disruptive if you want to keep it quiet. But mostly that it is annoyingly slow.
But I’ve had the same issue with too many warnings, mypy is better at understanding Python but even slower.
As for version bumping, maybe it’s just a me thing, but I hard fix a version and only update occasionally. Sure each update brings new warnings, but most of them are valid and if you only do it a couple times a year… not that big a deal.
The only thing I found it ‘missing’ was an indentation check (it’s in preview, I don’t turn on preview rules), but I realized it doesn’t matter because we also have a formatter running on everything.