PGvector is very nice indeed. And you get to store your vectors close to the rest of your data. I'm yet to understand the unique use case for dedicated vector dbs. It seems so annoying, having to query your vectors in a separate database without being able to easily join/filter based on the rest of your tables.

I stored ~6 million hacker news posts, their metadata, and the vector embeddings in a cheap 20$/month vm running pgvector. Querying is very fast. Maybe there's some penalty to pay when you get to the billion+ row counts, but I'm happy so far.