After much research we recently installed the Draytek Vigor2950G Dual Wan Router for a client to replace their NetGear FVS336G. I'm impressed by its functionality and sophistication for $475 USD. The NetGear's load balancing was simplistic and couldn't properly utilize the combined bandwidth of the customer's T1 line and Rogers Cable modem.
All of the customer's software applications are cloud computing based so our goal is to provide redundancy, yet still utilize all the bandwidth available for better performance. We also wanted stronger QoS for consistently clear phone calls over Voip.
We configured the Draytek to allocate up to 75% of the T1 line to Voip/SIP calls. The 75% can still be used by other traffic but only when it isn't needed for Voip.
There are certainly more expensive firewalls/routers with the same functionality. So far it's working great. I'll post again after we've had more time to put it through it paces.