Pros
SWA is a great place to work. If you're passionate about improving the building environment and pursuing a deep understanding of the building science, this is the place you want to work in. People working here are very smart and interested in what they're doing - they care about delivering a quality product.
SWA is like a big family, where you feel you're part of a whole, a piece of something which is moving forward, seeking innovation and better solutions. Even if you're "new" and not yet a senior, your opinion is still very much considered.
SWA has a pleasent office environment. Everyone is friendly and wil try to help you, if you have a problem. Office hours are not strict and you can work from home, sometimes.
Cons
Policies and processes are not very defined and it is sometimes difficult to get a full sense of what you're asked to do, especially during the first year when you don't have much experience.
There is a bit of stress related to "billable" time: upper-management seems always focus on "saving on budget" and you're asked to complete certain tasks in an unrealistic short amount of time, sometimes. On the other hand, there is a bit of wasting of time because of no clear processes and lack of coordination between people working on same projects.