Accurate enough that, if you are not happy, you probably don't want to take the real test yet.
But not as accurate as most people assume - standardized tests have pretty wide standard deviations. The real test has a standard deviation of just under 30 points. Our tests have a standard deviation of about 50 points. This means that, if someone were to take that same test again a day later with no additional practice / improvement / anything, that person would be most likely to get a score within 30 points (real thing) or 50 points (our tests) of their last score - in other direction.
How much time did you take between tests to improve? A lot of people will take tests too closely together - and then it's not at all surprising that you don't like your scores, because you're not giving yourself enough time between tests to improve. In general, I recommend spending a *minimum* of 2-3 weeks studying between tests (and that assumes studying most days, many hours a week).
If you think that might apply to you, read this:
https://www.manhattangmat.com/blog/inde ... many-cats/If you'd like to discuss your strengths and weaknesses and how to get better, first read these two articles:
https://www.manhattangmat.com/blog/inde ... lly-tests/http://www.manhattangmat.com/blog/index ... -the-gmat/Then, use the below to analyze your most recent MGMAT CAT (this should take you a minimum of 1 hour):
http://tinyurl.com/analyzeyourcatsFigure out your strengths and weaknesses as well as what you think you should do based on that analysis. Then come back here and tell us; we'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)