Pros
Good compensation, brilliant people, a technology leader, a chance to be at the cutting edge of electronic design. Since almost every chip that's produced uses Synopsys software, Synopsys engineers are exposed to tomorrow's problems today. The culture treats employees with respect, and people have the flexibility to get the job done as they see fit. Management is clueful for the most part.
Cons
EDA is a tough industry, with limited opportunities for growth. People are being asked to do more with less, pretty much everywhere, and expansion is mainly in the less expensive locations like India and China. Some parts of the company take "customer focused" to a fault, shifting resources to fight fires to the point where it's tough to complete projects.