Saw the post yesterday and the servers have been overloaded since then :( poo

Comcast does not throttle your bandwidth (as in, reduce your throughput). It applies QoS prioritization to your traffic if you are using above a certain percentage of all available bandwidth in your service group on the CMTS. This utilization is measured as a moving average over a period of, I think, 5 or 10 minutes. So if you're wailing away on a torrent, an http download, an FTP download, or any other kind of transfer (it's protocol independent), you are simply moved to the bottom of the list in priority until your 5 or 10 minute average utilization falls below the threshold, then you are granted the same priority as everyone else.

How we get "treated" during our large LAN so we are always getting the max speed, the headend supervisor moves us to our own service group. That way, even though we're always well above the threshold for prioritization and do in fact receive that lower priority, because we're the only one in the service group, there's no one to be prioritized behind.