You're lucky denben73. I have the same SBG6580 modem, and it has been unimpressive. When we had the wifi activated, everyone in the house (me, my wife and three kids) would constantly lose their connection.
It performs better with the wifi deactivated, however, it still reboots suddenly, usually at the worst times such as when my wife is about to teach English to one of her students in Japan via Skype.
Granted, this may be more of a issue with Eastlink than the modem. I sometimes wonder whether Eastlink is throttling its customers. They claim they don't, but it often seems that when we go to use more bandwidth, the modem mysteriously reboots.
Any thoughts on why this might happen, and how to prevent it, would be greatly appreciated.