The obvious downside is the number of examples computed. A simple unit test can easily take 100 times as long when property-tested.
Besides, it would be really cool to have property-based integration or hybrid unit/integration tests. Or even property-based E2E tests. Unfortunately, the setup of the example will almost always take too long for a relevant set of runs.
For instance: If you have a basic data model (say in sqlalchemy) and want to write property-based tests (say in hypothesis), you can relatively quickly derive strategies for the models (but beware of recursion and primary keys). But writing that model instance into the DB for running an example just takes too long for swift testing.
Besides, it would be really cool to have property-based integration or hybrid unit/integration tests. Or even property-based E2E tests. Unfortunately, the setup of the example will almost always take too long for a relevant set of runs.
For instance: If you have a basic data model (say in sqlalchemy) and want to write property-based tests (say in hypothesis), you can relatively quickly derive strategies for the models (but beware of recursion and primary keys). But writing that model instance into the DB for running an example just takes too long for swift testing.