Pros
They offer GC process. They have a good marketing area. They pay on time. They pay your certifications (only when you pass).
Cons
The salaries are bad until you have another offer or your get your green card. They don't easily rise your salary even when you are making a good profit. Sometimes they don't assign a project because they don't do big profit even when is your only choice and they could fire you because you don't get a profitable project for them. You are the best friend while you are assigned to a project, if you don't have they treat you bad and reduce your salary. They rather Indian people over other nationalities. They expect from you to be another Indian employee who just follow orders. They are more like a HR company more than a consultant company at least in USA.