In order to make sure that an online casino is reliable, it is recommended to check it on recommended sites that deal with reviews of online casinos, such as Askgamblers and Casino Guru.
This two sites you mentioned is no doubt, very popular in the gambling community, but then, since I have not used any of this platforms or site before, I wouldnt trust reviews shared there, especially if the site is not like this forum where users have absolute and total freedom of speech.
If the site is the type where there is an owner or group of owners who create the reviews themselves, and users are only allowed to post comments on the reviews, then I will not trust them because, there is a chance that some casinos can pay the owners to post a review that is biased and untrue.
This forum remains the best so far.