Pros
There are no pros to working in the US headquarters as an employee. If you work for the company on a contractual basis as a consultant, then you will be treated very well.
Cons
How much time do you have? If you enjoy having self esteem, autonomy, or dignity then don't work here. I am solely referring to the management of Authority Partners in the US. Since they are all perfectionists, they will expect their version of perfection from you. Good luck to you if you ever make a mistake that management notices. At first working for the company seems gravy as everyone seems nice, but then you will notice several things: 1)Only 1 person who has lasted in the company for 2 years 2) Management doesn't really care about your opinion...on anything 3) They will micromanage EVERYTHING you do. Their version of good management is to quietly praise you for a job well done, but violently admonish you for any mistakes.