I just purchased a 7700N to use at a different location. As it is wise to test things as soon as they arrived I hooked it up to my adsl line here.
My Netgear syncs at 28xxmbps with a resulting SNR of 6db. Attenuation here is 63.5db. I have a long line but it is very stable.
I was surprised to see that the Billion only synced at 18xx on the first sync so I checked all my settings and rebooted the router and saw no difference in the sync speed. SNR was the same at 6db and attenuation was seen as the same value - 63.5.
The Billion is destined for a location with a much shorter line using an 8mbps service I know I will get full speed out of it and will benefit from the 300mbps wireless too. But if I were to use it here then I would be losing 1000mbps of sync speed. Which would be the difference between a 2500 and a 1500 ip profile.
I am posting this to point out that difference that I have found between the two different Broadcom chipsets used here, 6348 in the Netgear and 6328 in the Billion.
Based on my brief testing there is no doubt which is the better router on a long slow line.
I have also used a Billion 7800N here for a few days. This actually synced at a faster speed than the Netgear but it is a big clunky ugly looking beast and does not fit in here so it was sent back.