Pros
Conveniently located in downtown SF, great food, nice architecture. The place is full of smart (but utilized people). In general, the company is design oriented. When Jack was the full-time CEO at Square, he was approachable, and had the company stand with a good head on it's shoulders. Jack and the Ops team focused the company to be socially aware, and promoted positive values unlike at any company.
Cons
Have you ever seen Silicon Valley where there are a bunch of employees who no one knows what they do? That's this place. There was little ethnic and no gender diversity on my team-- this is a problem in the modern world where products are built for everyone. I found that promotion from within comes from bro-deals and not merit. Compensation was about 15% lower than competitors.