Pros
The people are nice and if you are in an entry level job, the atmosphere is great. The speakers themselves are a great product and you can be proud of them. As a benefit you get discounts on the products. There is a very strong vision for the speakers themselves and the management will stop a product release until it is of a very high standard. This is a company you will either love or hate. If you are used to working in a structured company and executing on a strategy, this probably won't be the place for you. If you have a lot of energy and patience and can tolerate the churn and noise and just do stuff, then you will probably enjoy Sonos.
Cons
There are way too many people with opinions on how to do things, but not enough people to execute these. Everybody and their dog will have an opinion on your work and they usually won't tell you to your face. Either that or they will expect to have sign off on what you do. This problem is made worse by the time zones. I have seen things which normally take a short time in other companies get bogged down by every man and his dog wanting input. The result is usually a failed project which wastes time, costs a lot of money, leaves a lot of technical debt to clean up (which nobody does). The company is moving from being a start up to a mature company and is going through considerable growing pains in the change. They have hired very talented people, but there is a bit of conflict between the people who have been there for a long time and new people. The company is aware it needs to change, but really struggles at allowing people to make those changes. Again, the time zones make this even worse. If you want to make real change you have to be prepared to work with 3 different time zones (and counting) and the long hours that entails. In my experience, there is a lack of trust in middle/upper management and a general feeling of job instability as a result.