TL;DR: The best embedding model for chatbot RAG semantic search is the one that wins on your labeled retrieval set while preserving the fields your application needs to act on. For an edtech sales-call assistant, I would measure retrieval of the right CRM policy, objection playbook, and follow-up rule before looking at model size or price. The winning flow is: define the CRM action schema, build hard examples from real call summaries, compare candidate embedders with the same chunking and index,...