When i do gamble on casino site that is new to me, i will check the reviews, scam accusations for not paying the funds in bitcointalk since most of scam accusations and unbiased casino site reviews are posted here. i don't trust the casino reviews outside of the bitcointalk due to the possibility of fake and paid reviews so, i stay away from those sites. I don't usually deposit on new casino site unless the site have some free rolls test their site. Also, relatives and friends can also provide a trusted review since they tried the casino first.
I agree with you, bitcointalk is a reliable source of information regarding this matter. Even though paid reviews can appear here as well, they are getting many of replies pretty soon, and you can judge by yourself who to trust. Normally it's not that complicated because you can see the reputation of the posters. Btw, reputable gambling sites are getting bad reviews too, but they are either from newbies or from addicted gamblers who are just angry because of their loss. This can be easily spotted when you have many of other reviews in the same thread.