mourinhogmat1,
Thanks for your questions. I think regarding test scores, you can find all the information you need at:
http://lgo.mit.edu/engineering-mba.html.
For the class of 2013, the average GMAT score was around 710, and the average GRE Quant score was 760. LGO accepts either the GMAT or the GRE, though. You can take either exam, and definitely don't need to take both.
We're taking about 7 classes this summer, and the level of teaching has been incredible. Our Probability/Statistics professor is honestly the best instructor I've had at any level. In all, I've found the quality of teaching to be exactly what you'd expect from MIT.
Lastly, the program is quantitatively intense in a number of ways. Quite a few of our required MBA courses are cross-listed as engineering courses and are taught at a graduate engineering level. For example, our Systems Optimization class has us diving pretty deeply into concepts like linear programming, matrix algebra, and programming in Matlab. I don't believe there are any firm pre-requisites, but remember, you have to have taken an undergraduate curriculum that stands up to the admissions standards of the School of Engineering, not just the Sloan School.
Hope that helps!