I didn't particularly like the experience and it felt like lots of plumbing.
I would've expected tons of companies to provide now a simple interface to author text and have it automatically serve as knowledge for some model yet that doesn't seem the case.
Something akin Notion + prompt + get an API you can use against your knowledge.
The few Raas I've seen all want me to contact sales which to me is an instant no, and they also lacked some way to test the product. Or they didn't provide authoring tools, which feels a bit odd to me, as you're requiring a customer to set up all the plumbing just to upload some text.
At the end of the day it looked like the assistant API from OpenAI was the closest thing that could do it for me, but I don't trust the company much, and enterprise data privacy and GDPR compliances are a must.