I am interested in applying to Top 15 schools. Unfortunately, I have taken the GMAT twice before and received really poor scores. I would like to take it 3rd time. Due to my current job resposibilities, it is very difficult to concentrate on my studies. I would like to quit my job so I can focus clearly on my GMAT and the admissions process. Is this advisable?
Nah. Don't think chucking a job for GMAT makes sense. I know some people may do it. But, that's just insane because
1) in quest for a good GMAT performance you are going to be unpaid. (If you are a rich kid, uh, well then ya, sure go ahead. Hang up your work boots for a while!)
2) You will be losing valuable work experience. You will have a lot more to talk about work if you continued working. Break in your resume is not something B-Schools want to see. (But, lets say you can cover it up with a Entrepreneurship story / may be you really have a entrepreneurship line to continue working. In that case, you can always weave chucking job for being an entrepreneur story that sounds plausible.)
3) GMAT ain't really so hard that you have to quit your job to study for this test. So, studying GMAT alone does not warrant for quitting your job (may be you can study for your CFA and GMAT if you decide to quit your job).
That's my 2-cents. Of course, you are the best judge of your capabilities. So, make the decision to quit your job only after you have thought through all possible cover ups you will need to provide during your apps. A simple "I quit to study GMAT" won't work at all.
Good Luck eh!