Good article - the most use cases i see of pg_vector are typically “chat over their technical docs” - small corpus - doesn’t change often / can rebuild the index - no multi-tenancy avoids much of the issues with post-filtering
Chroma implements SPANN and SPFresh (to avoid the limitations of HNSW), pre-filtering, hybrid search, and has a 100% usage-based tier (many bills are around $1 per month).
Chroma is also apache 2.0 - fully open source.