Interested to hear any more on this. I've been using pinecone for ages, but they recently increased the cost floor for serverless. I've been thinking of moving everything to pgvector (1M ish, so not loads), as all the bigger meta data lives there anyway. But I'd be interested to hear any views on that.

It depends on your flow honestly. If you're just using your vectors for where filters on domain objects and you don't have hundreds of millions of vectors PGVec is fine. If you have any sort of workflow where you need low latency access to vectors and reliable random read performance, or where vector work is the bottleneck on performance, PGVec goes tits up.

At 1M embeddings I'd think pgvector would do just fine assuming a sufficiently powerful database.