K.
One of the times we have gone was the first weekend in Oct. it is a cheaper and less crowed time but it was so hot and very very humid. So humid that it rained for a short period every afternoon. I like going in early Feb. check the dates on their website b/c in Feb. it jumps from the cheapest time to the most expensive (spring break) in a day.
We have always stayed on ground, at one of the All Star resorts, they are the cheapest but you still get all of the benefits. It is so worth it and really not that much more than other hotels.