Chickee , I respond to your qn after I deal with some business
Makan24-7 wrote:
my next statement might ruffle a few feathers but there seem to be what we use to call "GMAT factories" in India and China
With VERY ruffled feathers

, I am surprised by this.
I'm from India and never heard of these factories which do produce results. If they do exist, I am quite confident that they are not a significant source of 700+ scores.
In India there are scores of institutes that cater to another exam called the CAT for entry into the hallowed Indian Institutes of Management (IIMs) . They have introduced some courses for GMAT . As far as I know the market for GRE factories is much bigger than the GMAT equivalent. I think its also got something to do with GRE writers mainly being students and GMAT candidates being professionals who do not have time for classroom courses and private study.
After that display of righteous indignation I may now get to the point
Chickee,
Like Makan24x7 said , its better to do your private study first and give some mock GMATs available on Kaplan/GMAT registration CDs to assess your strengths/weaknesses before you decide on a classroom course.
I doubt you will need it but also if you will have time for spending time on those classes and doing the mandatory private study.
Anyway , here is something wrote after I gave my GMAT - its a long post with info for test takers.
http://www.urch.com/forums/just-finishe ... -post.html
Use the numerous forums at scoretop.com , 800score.com , testmagic.com and pagalguy.com - many have tons of information , test taking strategies and problem-solving/verbal qn discussions.
You will find that hardly any of those who score 700+ and write their experiences like I did have actually takes a classroom prep course. Now , there may be many arguments for that , but I feel self study is the best.
Good luck.