What changed on your network a month or two ago? Before adding the HP and tablet, were the Dells getting great downloads?
I used a USB/RJ45 because I don't have a straight RJ45. Updated all Intel software on the Dell Laptop. Same symptoms.....still looking at Bridging the Cox Arris and putting in my own router back in to see if things get better.
Forget the RJ45. I'll assume you'll use the Dells on wireless. What changed on your network 1 or 2 months ago? Did your Dells ever get great downloads? What happens when you remove the non-Dells from the network?
It sounds like your router is lowering the transmission priority of your Dells, such as a Quality of Service setting (QoS). Are the Dells actually on your network or are they using the stronger wireless signal of your neighbor's unprotected network? Why are you on the 5 GHz band? Did you try the 2.4 GHz band?
