OK I'm also speaking on Derek's behalf. Those people who say (20 pgs WTF?) can be amazed if they so desire, but have no idea about quality vs quantity. The fact is, markers ARE influecned by quantity, they DO tend to give higher marks to more pages and if you have large, neat handwriting, they will only be fooled into thinking you have written more content.
Markers dont waste time tossing up how much someone has written based on handwriting size, wpl - they just mark the damn thing.
Also, chances are people who write that much are much better candidates:
A. They have taken the marker's opinion of them into consideration and this strategic gesture implies they are concerned with their marks.
B. They have probably finished MC and short answer more quickly because they know what they are talking about and so have up to about 1 hr 20 min on each essay. (this is not necessarily true as when pushed for time - english 40 mins - they can still do it)
C. They probably have a myriad of stats, relevant material at their disposal and since they are more prepared, they will not stop wriitng the whole exam and get more out.
Conclusively, anyone who questions the quality of a long answer is going to get CAINED!