We just returned and I'm not sure if I could do the end of August again. There would be some variables for you. Do you have children? How do you (or the kids) handle the heat? Can you possibly go at another time of the year?
I don't handle the heat too well. And, it was HOT! We also got the best of Hurricane Charley and were rained out a couple nights. It was also hard for the children to stand the heat.
We were only there for 6 days and didn't get much done. Last time we went was the end of September and we got much more done. The crowds weren't awful during our stay, but were not great either. We had to FastPass the rides we really wanted and just simply skipped many rides because lines were too long. I choose not to stand in lines longer than 20-25 minutes.
We've also been during April, May and beginning of June. Since our kids are now old enough to be in school, the beginning of June will likely be our chosen time from now on.