More on the GMAT vs GRE
I’ve gotten a lot of comments regarding this post about the GRE vs. GMAT. To be honest, the issue was not really about whether one should take one over another, but more a way to show that the GRE is accepted nearly everywhere, and to offer up 
the links to the schools’ websites regarding their preferences.
On LinkedIn I received this comment from Kate McKeon, an accomplished GMAT instructor, whom one of my clients is using right now. She’s smart and experienced, so I thought I would put in her response right here:
From my experience, the GRE can’t hold a candle to the GMAT in terms of ability to test depth of analysis skills. The GRE is a much “faster” test (question turnaround time is faster) and therefore more adaptable to memorization. I’ve taught and taken both.
My students report that the GMAT is strongly preferred at most schools, even by those who do accept both. The GRE is still treated like day old bread. Your Columbia applicant’s experience is par for the course. Columbia seems to be the biggest stickler (they won’t accept the GRE if you have ever or will ever take the GMAT), but the unofficial scuttlebutt is that the GRE is a weaker test for this candidate pool. If a student is weak on quant and very strong on verbal he/she may be able to get nicer percentiles on the GRE, but by taking the GRE is at a slight disadvantage in the application. No one piece of your application is likely to kill your overall app, but niggling weaknesses do add up.
To add to your mix, I had a fairly successful GRE-based applicant admitted on the condition that she submit a GMAT score in order to continue the program. She was given a semester to do so. First term of bschool seems like an awful time to study the GMAT.
Good stuff, and worth noting.