Taking the August isnt all that early. It would be one administration before the other people in cycle with you would. Here are some reasons many choose to do so if they have all of their pre-reqs:
1. Specifically for Aug 2006, it is the last paper and pencil test.
2. Availability of a whole summer to prepare for the test.
3. Material is fresh from the courses.
4. Get it over with or be able to retake in April without having a late app.