That "thing" uses your home wiring to carry an ethernet signal, and the claimed data rate (500Mbps) is probably better than AT&T can provide, but most reports I have seen for similar devices often complain they are slow. This is easily tested: With your laptop connected to the Powerline® adaptor, log on to
Speedtest.net (it is free and accurate) and will tell you what your
actual download and upload speeds are. Try that at different times of the day and from you desktop as well as your laptop.
Like WiFi there are a LOT of factors that will effect the speed through your Powerline® adaptor. Mostly line noise created by electric motors (think air conditioners, fans, refrigerators,
etc. and florescent lights. (If you are in an apartment or condo that interference may be coming from anywhere in the building, but generally it would be limited to a device(s) connected to your electric meter. While I have not experienced this personally I have read comments indicating these devices tend to slow down with age as well.
NOTE: the maximum segment length for Category 5 ethernet cable is 100 Meters for 100 Mbps data rate. 1,000 Mbps would be significantly less but unless you are living some place like Buckingham Palace cable length is unlikely to be an issue regardless of that the technician says unless the technician is using substandard ethernet cable.
