i traveled to CUN last year for work during late March from PHX prime time for Spring Break. I was on company business so I was positive space but let me tell you the flights both ways was jam packed. Spring break to Mexican beach resorts can get a bit iffy, CUN in particular as it is one of the most popular resort towns. I would not worry about crime in CUN, the city has been hardly affected by cartel related crimes.

Regards,

Chepos