Avantages
The work environment is great at MathWorks for engineering. I've read other reviews that say you have to "drink the kool-aid" in order to succeed. To them I would say, "oh lighten up". If you are a good engineer and you are excited to solve cool problems and can work well with other people, then MathWorks is a great place to work. If you are a cynical uber-nerd with a chip on your shoulder and you constantly roll your eyes every time you hear the phrase "core values", then no, MathWorks is not a good fit for you (nor will any other company be, you will find). The salary is not the best, but it's probably in the top half of comparable companies. The perks are great. The owner (it's a private company) is super generous. Plus it's MATLAB! It's cool to be a part of that.
Inconvénients
Your mileage will vary based on who your manager is. I'm in a great group, but I know there are other managers who are not as good (I worked for a couple).