Yes! It is HOT and crowded in Aug. But, it's still wonderful.
We spent 3 days at Universal in early Aug of 99.
Keep in mind IOA was very new. If you have the luxury of FOTL and EE, I wouldn't really worry about the crowds. Just start the parks early, and take a mid afternoon rest at the hotel, pool etc. and get back out around 6ish.
For us, the bigger issue was the heat! We live in a very humid warm area but, aug. on Florida concrete was tough! Have lots of hints for the heat if need, just ask. Lucky You!