I do read casino reviews before depositing any amount. If I am convinced to the negative reviews, I would hold myself from playing to their site.
Useful reviews should contain first-hand experience narrative or any other ways to do it. It should also contain evidences to support all claims that the review author has written, otherwise, I won't find it useful, unless there are some reviews that tells the same thing (but has given supporting details to their claims).
Individual review, as I prefer, should have no referral link at all.

Welcome to the forum, best of luck!