Pros
1. MathWorks is a great place to start one's career. This is true of several of my peers whose first job was at the MathWorks. 2. It feels good to work among so many very intelligent technical people. The work environment fosters intellectual development. 3. The percentage of people who've stayed for over 5 years is significant - make what you want out of this indicator, but I'd say there are strong reasons why a lot of good people "check in and never leave"!
Cons
1. While the company is a great place to start right out of school, one might face roadblocks to growth after 3 or 4 years. The company is good as a launching pad for one's career, but you might want to look ahead a few years to see whether there are opportunities for you to grow. 2. No one will likely discourage you from going out of your way to contribute....but no one will encourage you either! This "con" could actually be subjective and team dependent, but there aren't any concrete steps in place to encourage people to do more, and there are limited means of rewarding them. If you've really gone out of your way, gotten involved in a lot of things outside of your job description and done great work......good for you! Just don't expect anything in return.