me and my kids went in Febuary - and we had a great time.. it was a little over a hr from negril and you go through working sugar fields and then mountains and rainforest.. the trip alone was enjoyable for us.. then the falls - lots of natural jacuzzi massage points - i and as shellyk said the place you can jump and then go through a underwater cavern to the other side.. no crowds - plenty of privacy actually.. then have your driver go through sav la mar on the way back - if you have never been there is it a experience in itself - lots of good shopping - and really see the local culture and way of life in action..
do a search if you care to on the old board for mayfield falls - i had a trip report write up on it in febuary.. lotsa nice pics