Pros
Products are the best in their class. Management has a long-term and very ethical way of doing business. Developers and technical people get a lot of respect--maybe too much. Small, effcient teams of competent individuals. Very effective communication across the company via networking activities, intranet,etc. Results-oriented, factual, and quantitative management style. The MathWorks is a well-oiled machine which you will enjoy being a part of if you are (i) results-oriented, (ii) hands-on and pragmatic (iii) not overly creative (no time) or individualistic (iv) patient
Cons
Due to the heavily quantitative management style, people sometimes work to meet metrics and not always to meet customer needs. Tends to be very internally-focused. Extremely risk averse culture--sometimes to the point of stunting creativity and killing opportunities. Quite a bit of reporting and overhead for such a small company. A handful of developers have developed attitude problems, probably due to a combination of ego-inflation and stress.