I had a good experience with InterSys.
Their staffs are very responsive. Within several day I post my resume, I got interview arrangement. Before the offer finalized, they followed up very week. When I had to postpone the start day because of family emergency, they helped me to extent two weeks. They were also very cooperative when I finished my contact and convert to full time employee. Besides, their coordinator for NYC office is very nice.
I am lucky to have InterSys helping me at the beginning of my career.