Hi! I'm the guy who made Dot. I remember experimenting with a few different vector stores in the early stages of the project but decided to settle with FAISS. I mainly chose it because it made it easy to perform the whole embedding process locally and also because it allows to merge vector stores which is what I use to load multiple types of documents at once. But I am definately not an expert on the topic and would really appreciate suggestions on other alternatives that might work better! :)