Pros
Etherstack is an absolutely outstanding company, both from an Engineering and a Personal perspective. Engineering: A lot of admiration and respect for what Etherstack does. Very interesting field, with a lot of opportunities for learning really cool stuff and develop a wide variety of skills. Personal: People are just really nice and there's an exceptionally good environment at the office. Also the Engineers are some of the smartest and kindest people I've met, super helpful and with a very good sense of teamwork. Management's attitude has also been impeccable. I had to face a very serious personal issue outside of Etherstack and the response from Management was mind-blowing, extremely supportive and understanding.
Cons
Not easy to think about the cons. Maybe the size of the company if you don't like DIY environments, but I guess a lot of people would actually consider that a pro.