Which socket?

[#1]

have you got a laptop or desktop pc you can ethernet to the plug your going to connect your ps3 to.
as important as throuput is i think as this setup is for your ps3 runing some pings/tracerts to see what the latency is of the home plugs would be a good test to do as well as throughput.
is that 82 figure runing the home plugs over the trip switch?
just had a google about testing the throughput and seems most people who review these products just transfer files and work it out that way.
i didnt look very hard so maybe there is a program that will do it with more deatil.

[#2]

Yes I have lappy and desktop how do the ping/traces? The wallplugs appear to traverse across the trip switches, the ones I have are plugged direct into a double socket that is on a seperate main on its own trip switch, this I know for sure because I fitted the double socket and wiring myself so I could put my desktop under the stairs with the router right next to the phone socket and fuse board.
I'm getting the readings from the furthest socket downstairs havn't tried up. I don't think that distance is a major player though tbh I think its more the quality of the wiring. 

[#3]

just do a simple command prompt tracert to bbc.co.uk.
type cmd in the seach menu on the start menu.
then type tracert bbc.co.uk
the first hop will be your router. unless the home plugs work diffrent to wireless. but just look for the ip address that use to log into your router
hopefully your ping time to the router will be 1ms all the time.
you can also use programs like ping plotter to monitor over a period of time http://www.pingplotter.com/download.html
the download link for the freeware version is right at the bottom of the page.