The 811 is a terrible piece of equipment. I have my 510 connected where I can switch back and forth between the 811 and the 510. The picture quality on the 811 blows.. sorry best work I can find to describe it. I will be sending it back for another 510, (one I'm using now is from the bedroom), it's junk anyway you look at it. It does provide a HD signal for dish, but for that you get SD channels that look worse than Cable tv after its been Tivo'ed.
I'm not like many who had to sign a 1 year agreement, I would recommend calling Dish and complaining. They will send the dang thing out to anyone who is thinking of leaving for no charge and no agreement. Wish it worked, but having HD is not worth having the sh#$% looking SD.