Used this service twice for my boss's business visa. Not only are they quick and efficient there customer service is beyond helpful. I would call probably 2-5 times while filling out his visa to ask a question (as these applications are very specific) and every customer service representative were super knowledgeable, they never had to say hold on let me check, they knew every answer right away. Were happy to help and even offered to walk me through some things. Also, for me at least, one of their offices is located in Grand Central, a five minute walk from me.
I will definitely have to use them soon again in the future as my boss's international travel is increasing -- I am not sure how I found itseasy but I am so happy I did!