The RIU guidebook is the same language at most all coastal properties it is the same guidebook as Club, Ocho, Mo Bay, the Mexican properties, and Costa Rica. I drank it just fine not too mention if you are worried about drinking it feel safe in the fact that included in your rate is free bottled water which is kept stocked and in liter bottles shipped in.
The bad reviews against either of the RIU properties stem more from people angry they didn't do their homework and have realistic expectations.