Pros
Firstly, what3words values its employees. They want you to know that they are all in. The company HQ is in London but at the beginning of a project they schedule meetings with staff outside the UK (in my case Bulgaria). They make sure you understand what is expected of you by explaining everything at length. That way there are very little problems during the course of the project. Secondly, the pay is great! It is on time and you can choose how to receive it. Furthermore, there is no pressure from the company during the project. The deadlines are convenient, so much so, that you would never have any problem finishing on time. The correspondence with the project coordinators could not be better. They are available for questions and are very understanding. If you have the chance to work with these people, don't miss it!
Cons
None that I can think of.