I recently had BT infinity installed and disable QOS / banwidth management on my 2820n as this was affecting the upload speed reduced from about 16mbs to 8mbs (posted in another forum). So this now working wired at 70/16 mbs.

the 2820n is in a side loft and generally not used for wifi
but when I connect to it (with good signal strength) I get good download and up load speeds

I have an AP 700 (Rev. A FW1.15) wired into the 2820 as well but no matter how good the signal strength is I am now getting alot less than 1mbs download and 10bms plus upload on either smart phones / laptops etc.

I have verified that there is no other APs causing interferance, disabled / enabled WMM. re-enabled QOS bandwidth management on the 2820

before infinity I didn't notice any problem but I cannot be 100% the two are related..... (does not see logical to me that they are..)

What channel are you using on the 2820n and what channel on the AP700? Remember, if you are using wireless n, then the two need to be at least 5 channels appart to get full throughput. Best to use 1 and 13, 1 or and 7 or 7 and 13 but also depends on other APs in your area.is the AP700 set up in AP mode as it is wired to the 2820n?