I have worked for a lot of recuiting services. This one isn't bad, if not a bit less professional. There was issues with payroll that never really got fixed. After a month, I just dropped it. There was also some scheduling mix ups. I got re-scheduled for an interview but didn't get the memo. I don't what know happened there. I asked what happen, but got no response. rather odd.
I would use their service. Just keep in mind that they feel like a small company, whether they are or not.