Pros
They will help you a lot to grow in the US. I began in Presidency Solutions with a little experience, other developers took a project in less than 1 month, I wait more than 1 month because I had problems with my English and I didnt have too much experience. But I am glad to had this opportunity because right now I am working and the salary is great for me and better than in Mexico. So it depends on you the time that you will spend without the project, the recruiter told me that before I accept the offer. If someone didnt get a project is his fault.
Cons
The beginning of the process is a little slow but it depends on your experience