walker
My 2 cents. GMAT tries to predict your academic success in b-school. Why? CR+RC+SC is almost equal to cases: you need read carefully, fast, be critical and write a good write-up. So if you fail due to language barrier, you will fail in school for the same reason. Believe me, it is not easy to be a non-native English speaker in b-school and GMAT helps you to be prepared. You can't imagine how difficult it is for the person who have never spoken English before. I was in your shoes with 25% success rate in SC after 2 months of intensive GMAT classes. So, don't try to find excuses, just do as much as you can to learn English, not just for good score, but for ability to get much more from b-school later. By the way, I'm not talking just about academic success. For first 3 months I hated myself that I didn't spend more time on English because I can't socialize, express myself properly and so on.
You are the man! I got this idea after ~15 days of the preparation. I was feeling sick to start with. While reading RC/CRs, I used to be like WTF?... I just don't know what this means. What if I misinterpret it? Will I get all the questions wrong? Will all the time spent reading this passage be in-vain as I will get all questions wrong anyways? Even worse when in the 1st line of the RC you hit some unknown (for you but common among the native speakers) word(s) that you have no freaking clue what-so-ever. That's a very depressing scenario. And EVERY non-native speaker goes through that. Just keep chugging! It only gets easier and you start making right assumptions of these GMAT's tricky words, whose meanings are sometimes not that difficult to guess.
Anyhow, point I am trying to make is - GMAT IS A NECESSITY FOR MBA (period!). In the past couple of months, I can't even imagine how much I have improved. I feel good about myself. I have written few recommendation for promotions of my colleagues in last 15 days, and I can see a drastic difference in my presentation of ideas and my choice of words. I did an interview of a candidate 10 days ago and wrote a full review of the candidate (that's a normal protocol at our work) - In my 5 years, I have never written such a review; My CTO sent me email the next day appraising it whole-heartedly, thanking me and saying one of the best reviews he has read. What I used to consider flamboyant while reading/writing, is now soothing to me! I am enjoying the whole experience more than ever. No matter what happens, I know GMAT is teaching me many things and even if few consider GMAT biased, I praise it WHOLE-HEARTEDLY. In modern era, ENGLISH IS THE MUST!
My one and only advice - ENJOY the experience! Feel as-if GMAT is doing you a favor by making you learn the MOST IMP aspect of your being a professional (period!).