Most of your configuration, shouldnt be necessary.... and i think most of your issue, might have been stemming from the routers you were using with it initially?
I am guessing most of the older routers you were using, were only 10/100 on the wan?
Not that there is anything WRONG with them.. and they should handle your speed package fine..
BUT there is a bug, where the devices dont link nicely with 10/100 devices.. causing bad linking, and not proper/maxed speeds.
(this is somethig that still needs to be fixed by rogers/hitron)
This seems to effect both bridge mode and not, on both new and old firmware.
But now that you have a full gigabit router.. and the latest firmware.. i would try full bridged mode again.
The one thing i would be worried about your current config.. would be everything is still passing through the cgn3s firewall, etc... your efectively double NATing and Firewalling your whole connection.