Critics have also stated that the computer-adaptive method of placing more weight on the first several questions is biased against test takers who typically perform poorly at the beginning of a test due to stress or confusion before becoming more comfortable as the exam continues.  On the other hand, standard fixed-form tests could equally be said to be "biased" against students with less testing stamina since they would need to be approximately twice the length of an equivalent computer adaptive test to obtain a similar level of precision. 
Yes. However unbelievable it might seem, your friends can sometimes help you get better marks. They can help you identify the mistakes you did not find obvious enough, and you also get an outsider’s opinion on your essays, and therefore on your points of view. Now, even though your friends might be untrained, or unaware of the GRE AWA grading system, having a second pair of eyes look at your writing can be really beneficial to finding your flaws. Plus, you receive feedback then and there, right on your face, and it is sometimes the easier way to learn.