Pros
Synopsys is on the cutting edge of silicon valley technology. Its a great people friendly culture that has many opportunities for growth. There are many bright people here to work for, given that it is in the EDA industry which means that you need a masters of PhD in EE to understand what the advanced software that they design does. (Designs computer chips is a good basic overview of what the software is used for). I would highly recommend working here, as I have not met anyone who is unhappy and looking for a job somewhere else. Become a synopsoid!
Cons
I would say the only downside is that it is very hard to understand the product that synopsys makes, from a business perspective. Everything is extremely complicated and must be explained by an engineer if you are to understand what is going on. This can make it hard to really see what is going on when you are doing the business model, because these companies that you are working with make products that are near impossible to understand. Even though there are cheat sheets provided to sum up what is going on, it is still very complicated and confusing at times.