hi,
honnestly I think that with a 690, you will have no trouble with the GMAT hurdle.
I mean that a low GMAT can prevent you from being a potential applicant in many schools but a good GMAT can not make you accepted either.
The objective is to have a good score but except if you really score 750+, you will have to show a lot of other skills, experiences and motivation during all the MBA process to be accepted in any school.
I really advise you to take more time to write your essays, visit the schools, contact alumni and current students, ....I think that it will be more valuable than a 700+.
Good luck
Antoine