After writing the GMAT, I strongly believe that
1) What you will score on the GMAT will be close to what your have gotten with your prep tests.
2) As long as you are able to present your views, the strict grammar that was tested in the verbal portion of the GMAT is not actually required in the AWA essays. Look at my score V31 and AWA 5.5.
3) No matter how much preperation you do in the Quantitative portion of the test, you will never be exactly prepared for the questions on the GMAT. I was able to get Q51 on Princeton and Q48 on Kaplan
, but only got 46 on the GMAT.
4) your score is a representation of your ability, and GMAT judges your ability quite well. If you are not confident entering the exam, you will prob not do as well. However, if you are confident about your abilities and you thought you did horrible on the GMAT, you prob did as you expected prior to the test.
I do not think I will do the GMAT again (unless I do not get accepted), but I have got to thank GMAT for improving my English ability and as well as giving me a challenge.