Of all the people called to an interview, what are the main factors that determine which group gets accepted?
Is it 100% the interview, or does your MCAT/gpa still play some role?
		
		
	 
That's actually a question for which the answer may vary. It's like you applying for a job as finance officer for USA Bank, Target Corporate, and FedEx Freight.
I may be the ideal financial officer USA Bank is looking to hire, just average for FedEx, but not so much for Target Corporate. 
What each college is looking for in a student is similar in a lot of ways, but generally varies.
The people looking at your application will like your stats and pull you in for an interview. Then they will look at you as a whole. 
Interviewers are 
human. I can't stress that enough. Some people suck as interviewers. Some people are great. 
Still others are awful at picking out what would be a great student/employee 
for the college, and some are great at it. 
Long story short---just like a job interview, if you go you have nothing to lose. Give it your best shot and let it go. They'll contact you if you caught their eye.