I went to Cancun for a company event in December. Great weather, good water (for now)
I watched a documentary about a month later on what an environmental trainwreck Cancun has become.
They have essentially polluted all the natural water sources, and are pumping millions of gallons of sewage just a few miles of the coast.....as well as rapidly overdeveloping the area.
IMO, the key to Cancun is to avoid Cancun. Cancun has been taken over by drunken twenty-somethings who are in all-inclusive deals and want to get as much booze as possible.
are certainly spot on as well.
I'm glad I didn't spend my own $ to go there.....would have been very disappointed.