My experience with Finquiz (from Level 2) has been a very positive one.
In my view, Finquiz Notes are a companion, not a supplement, to the CFAI text.
And this is exactly how they describe themselves in their website.
In 90% of the cases, I just read the CFA text to have an understanding of the topic and then used FinQuiz Notes for retention & revising. This way I could judge the quality of the Notes without fear of having ommitted important material from the CFA text. The last months were only about Finquiz Notes. Economics was the only topic that wasn’t covered well and had to rely on the CFA text instead.
So in a nutshell, FinQuiz is for retaining & revising material and CFA text is paramount for examples (blue boxes) and EOC exercises. Throw-in the extensive QuestionBank as well and you have a winning combination.
I’ve also subscribed to their L3 Notes, but they won’t be accessible till late September