Thanks for your interest, rahulmitra.
I have been running a GRE AWA study group with Chinese-speaking test candidates since this July, and I have three active members (whom we refer to as "writers").
The study group is based on peer-reviewing (PR). Each week, we have ONE timed practice (TP) session and ONE untimed practice (UP) session. During TP, every participating writer writes a response to a GRE issue or argument topic within 30 minutes; when time's up, the writers swap their essays, begin PR, and provide feedback based on four major criteria recommended by
Magoosh: "quality of Idea," "organization," "writing style," and "grammar and usage" (I'll show you their respective sub-criteria when I become eligible to post a website address).
Please note that each member must be present at least twice per two weeks, whether or not they join a TP or UP session.
Let me know if you can dedicate yourself to honing your writing on a biweekly basis to achieve a 4.5+ in AWA. The UP session occurs on Thursdays, 1900-2100 PM (GMT+8), whereas the TP session takes place by only appointment.