Well the students I talked to said that a 7xx is all you need, but that some top firms will pay particular attention the quant score. All I was aiming for was a 700 so I am ecstatic with a 740. There are some previous posts on gmatclub about this. One person quoted GS i think it was in the recruiting process saying that they said "well you don't have to have a 750 to get an interview.." meaning that they like the really high scores and that they are looking for "pure mental athletes." So I guess the bottom line is if you want a job at like a BCG or GS, get the highest score you are capable of. By no means will it get you the job, it will just get you more interview opportunities. The biggest reason for my jump from 690 to 740 was
manhattan gmat's number properties book, I can't believe I even took the GMAT at all without a solid understanding of prime numbers....the GMAT is obsessed with them I think.