For those going for a high sore, the take home message from the two posts: aim for a 9 or 10 — or, aim for an 11 or 12, but be satisfied with a 9 or 10. Based on 2006 data, only about 0.7% of those who take the test receive a 12, and only about 1.5% of those who take the test receive an 11. In other words, getting an 11 or higher puts you in the top 2.2%. Only about 6% get a 10, putting you in the top 8.1% or so. Getting a 9 still puts you in the top 19-20%.
Most people should aim for a 6-8: the mean score is about 7, and 2/3 of the test takers received a 6-8.
Some essay advice: write a lot (try for around 400 words), and write neatly. Make it look organized and intelligent, and you will get a better score than otherwise.