Pros
The breadth of technical challenges you face at BrowserStack is hard to find in most of the companies, especially based out of India. Its an ideal place for a person who has interests in hacking on new problems across a wide range of technologies. At BrowserStack, your technical know-how increases tremendously as you're working on a purely technical product with a good tech team. And of course, since BrowserStack is very popular among the web development community, you have a great audience to build stuff for.
Cons
BrowserStack is part of a big community of web developers, QA engineers, automation engineers, etc. A lot can be gained by sharing the tech knowledge with the community via blog posts or open source contributions. This is currently difficult to achieve as the complete focus is on developing a cutting edge product.