Pros
The culture at ThousandEyes is something really special. It's a culture of excellence without egos. Everyone at the company is motivated and top-notch, without exception, but everyone is also accessible, helpful, and open to feedback, without exception. As an engineer, I also find the product really cool and fun to work on. It's really technically challenging, and it's rewarding to know the software we write is actually what the company is selling. So anything we do to improve the product or the user experience is really valued by the company and the users.
Cons
Even though I feel good about doing some small part to keep the Internet up and running, it's not always easy to show off my work! The product is quite technical, so it's not that easy to explain to people. But, like all ThousandEyes employees, I don't have a big ego, so that doesn't really bother me. ;) I find the work environment much more important to my happiness.