I have a 2850 on Virgin 100mb and get the full speeds upload and download. I also have a BE 20Mb connection which I can also max out at the same time.

I've got the full 76Mb down and what I think is, the full 16M up on a plusnet "up to 76/19.5" connection, equivalent to infinity 2 on 80/20 service. Which was a nice surprise because I thought I would have run into problems on the 2820 router.