A couple of things you will learn are the words "we" and "our." For instance: "We made the decision to go to Cancun for our honeymoon in May.
Seriously though, Dreams Tulum is a solid resort in all aspects(service, rooms, food, locale, etc). Look it up. As previously stated, try TripAdvisor. Also, after you get a quote from your agent i'd look up the same package on Orbitz or Hotwire. I would bet you will get a better deal. I've gone to Mexico several times using these sites and it's always cheaper for the same product. Google "orbitz promo codes" too and you can usually get a couple hundred off of a week stay.
You will be glad you expanded outside of your previous intention of staying domestic for your honeymoon.