I took the test today and got 740 (49/41, 97%). The journey finally ended here.
I think GMATprep helped me a lot. Of course I had spent some time with 1000 questions and the sets from the old GMAT tests. Try the GMATprep as many as possible before you go to write a test. If you can get 700 and over consistently, then you may go for a real one. OG is a basic. So for a starter, OG is a must item.
For me, verbal was a weak point. I have not been focusing on math as seen here with the test score. Some math background gave me that sort of confidence on math...
Anyway, keep practice! Then it will sometime provide you with a good pay-off. Good luck everyone! And thanks, beat the gmat!