I just spent several days in Mexico touring hotels so that we can provide our clients with a first hand account of what the resorts are really like.
An online site will only show you pretty pictures. We've been there. We've eaten the food. We've slept in the beds. We can help you make the best choice for you. No online site is going to do that for you.
However they will be happy to take your hard earned money, without one ounce of concern about whether or not it's the right resort for you or looks anything like it does on their site. And then if you have a problem good luck in trying to get someone to help you from your on line booking!