We went with DJ Mannia for our wedding which was in June 2012 in Cancun at the Fiesta Americana Condesa hotel.  We shopped around a lot for a DJ. Our main concern was that we were having an Indian type wedding and our guests wanted to hear both Indian music and American music.  Mannia assured us that we would get someone who would do know both, and they delivered...100%. 

They sent us a form about 6 weeks before the wedding and asked us what music we wanted, didnt want, etc.  We gave them a long list of the types of songs we wanted played, and they were really excellent about it all.  

Our specific people were DJ was Armando Patiño and MC Samuel.  They were great!  But, I didnt know who they were until the day before the wedding. I guess we just trusted the company because they had such good reviews and they were so responsive over email.

Our guests just wouldnt get off of the dance floor from the moment the music started till it ended.  And it was so hot inside that they ran to their rooms, changed into shorts and pants, and came back down and continued to dance! It was amazing!!

Do it. They are worth it.