I really like numbers and tables. Much more than texts, as those are clear, objective and easily comparable.

However my first point would require text, and that s an archive of the casinos current and past Term of Service and Bonus Terms and highlighting how often it changes and how. I heard of cases where someone won big with bonus balance, completed the wager and he was not allowed to withdraw it because  on the fly the casinochanged the Bonus Terms to include the game he just played on as restricted slot. This would show how often does a casino do such things, which could be a strong red flag.

Shortened, understandable ToS, especially highlighting unfair points. (Though most offshore casinos have such unfair terms that this point might be totally irrelevant.)

For cryto casinos it would be nice to know which coins are accepted and on which network, also how much fee do they charge for withdrawals for each coin-network pair.

Again for crypto casinos: what currencies do they support and whether or not a player can change the currencies they play in anytime, or is it fixed at registration.

For fiat: list the different deposit and withdraw methods, and warn the player if there is such a deposit method that has no withdrawal option too.

Presenting the loyalty program, preferably with numbers included.

Presenting the various bonuses and their terms.

Making an indicator about how good a casino is rtpwise. Have a good rating if they licence the slots with the possible highest rtp, and lower and lower as they license it with worse and worse rtp. (Like how the same pragmatic play slots can be licensed with 96% rtp, or 94%, or even less. This is true for many other provider.)

Showing whether KYC can be done before the first deposit.


This is all I can think of right now, that I think most review sites lack.