Crowds are do-able, but Disney tries to pull them in with the free dining offer, or a few year ago they went with the "pay for four days, stay for seven" deal. It does up the crowds somewhat, but people are still leery about the hot weather and hurricanes, so if they can pick another time they will.
We like it! DH loves the whole "vacation in the tropics" feel of Florida in August. Just don't let the heat build up on you. Stroll, don't run, around the parks. Cut through air-conditioned stores as you go along to get a few minutes of relief. Drink tons of water. I bought one of the watering fans they sell all over the parks, and I carried it every day! You turn the fan on, then mist water through it. I loved it!