I can speak about the dental school, not the medical school. Columbia is a school that puts huge influence on the DAT score, and not so much on the GPA. Generally, people who ROCK their DATs will have a decent/great GPA anyway, but that isn't necessarily the case. At the dental school (this is just from memory...) there were something like 12 minorities (in the most recent class) and I think 9 of them were in SMDEP somewhere (most were at the Columbia d-school). The diversity department has a say in admissions, if they didn't, why would they exist?
Also, for instance, let's say I'm applying for Dental School at Columbia. If I have a LOR from the head of the Diversity Dept. of Columbia, don't you think that would carry some weight?
We had many meetings about admissions, and at the end, they told us, that if we could get over a 20 on our DATs - preferably >22 that we should call/email them and remind them that we went through the SMDEP program there and the great score we got. They obviously couldn't guarantee admission to the school, but they said that they would help us as much as they could.
I think going to the site where you would most likely want to go to school would be a good idea, and unless you do something really stupid while you are there, it can only help you.
Congrats to everyone that got accepted! 😀