I just took the GMAT and got a 710 (94%) but only a 42 (67%) in quant and a 45 (98%) in verbal. I have a strong GPA (3.73) from a good undergrad program and 4 years of consulting experience. I'm targeting Chicago, Wharton, and NYU. My question is: will the quant/unbalanced nature of my score kill me? Should I consider taking the test again?

You didn't say what your undergraduate major was, but your Q score will hurt you at those schools, especially Chicago & Wharton because they are naturally among the most selective to begin with.

Here are some quotes from actual admissions directors (as quoted in Montauk):

"The GMAT is the equalizer, the only thing everyone takes. We do validity studies of it every year. There is a close correlation with first-year grades. Given that our program is quantitative and demanding, it is no surprise that there is an even closer correlation between the quantitative score and first year grades" (Mary Miller, Stern)

"A study we conducted regarding the GMAT quantitative score suggested that when someone scored below the 75th percentile, he or she was much more likely to have trouble with our program. We use this as a watermark, not a cutoff. If someone scores below the 75th percentile, we examine his quantitative course work and his professional work (to what extent he's been using numbers and formulas), and pursue the matter with him in the interview. If we like someone, we may admit him conditional upon his completing appropriate coursework: (Sally Jaeger, Tuck)

"We might not really look at the total score: We might concentrate on either the verbal or the quantitative score, depending upon the person's background. For an engineer, we might look at the verbal score to make sure he has the necessary skills. For a foreigner, we might want to see a 35 or 40 verbal score. The total score can be a matter of someone excelling on just one-half, so we want to make sure that that's not the case" Rod Garcia, MIT

I think the common theme is if your Q score is low, you are going to have to show elsewhere in your application that you can cut the mustard. A 3.73 GPA is good, but probably won't offset your Q score if you were an English major, especially at the schools that you listed. Wharton and Chicago both state that they like to see 80th percentile in both.

Where did you see the 80th percentile thing for Chicago?

I'm at 78%

At the Chicago thing I went to on Friday they said they were most concerned with overall score. But who knows.

I know a guy who got in wharton last yr with 74% in Q.
So as long as you can back up your Q skills, I don't think your Q score will be the show stopper.