I have been an ATG client for over a decade. In all of my interactions I am treated as if I am their only customer and my issues are of paramount importance. The combined knowledge and professionalism of the staff at ATG is unparalleled. There is no one I would trust more with my network security.
Do not call these guys if you are a small business. I had a couple of issues with our network in one of my businesses that were handled by them in a satisfactory manner. However, today out of the blue I got a call saying that they are not interested in small clients anymore. (this particular business of mine is a commercial printing plant, it has its own management and I am an absentee owner) They wanted a retainer of 14 hours at $165.00 per hour in advance for no reason just to make themselves available for a service call in the future. They said they would write me back with some referrals since they were not interested in doing small work anymore.
I love this company it is great. Have you tried turning it on and off again just a hint!