I bought several Manhattan GMAT products and they were really helpful for my study. I had less than two months to prepare for the exam, but I was able to score 710. Although my score might not be enough for getting admission to the school I want to get in, I am certainly happy with my first time effort.
Again, thanks Manhattan GMAT!
PS. This section might be a wrong place for posting this, but I don't know where else to post.