To: epony
Dear Epony,
upon finishing the gmat course, i was really left with no room for mistakes. on the weeks prior to the test i took at least one test a day ( usually 2) and spent the rest of the time analyzing the results. i think that once you reach a level in which you know all the reasons for your mistakes and you just have to apply your knowledge ( this situation for me was achieved with Eirene's help) then you're in a good place. i think the total time i invested in the gmat is somewhere in the vicinity of 3 months. hope i helped,
yoav caspi