When I tried it I got horrible speeds even on the same circuit. Not enough to sustain smooth video streaming from my server which was the whole intent. Repackaged and RMA'ed.
Out of curiosity, what were your download speeds and uploads speeds using powerline? How old was the construction you live in? How would you describe the wiring in the home? eg. Code, good, dangerous/fire hazard. Was it a gigabit powerline kit or did it have a 100mbps switch?
On my netgear wifi kit with the 100mbps internals (was a 500mbps kit) but meaningless because of the 100mbps internals. Downloads were from mid 50's to 60's mbps down and 13mbps up. That was the kit I just replaced.
This new TP-Link is top of the line 8370 gigabit kit with wireless AC built in. Has all the router settings built into the TP-link app. You can change the channel width on both 2.4ghz and 5ghz bands. I get on dslreports speedtest up to 165mbps down and 13mbps up on this new powerline kit. I have been doing research and I think those are the fastest speeds of the AV1200 kits to date for internet download speeds. I was going to start a thread to see if anybody with gigabit connections or something faster than my 240/13 speeds has obtained better results.
My opinion is slightly different than most. Ethernet is clearly the best connection to have. I think powerline is a distant 2nd but definitely more stable and reliable than wifi. I use powerline only for my gaming PC two floors down from the router and modem. It's surrounded by concrete and earth on two sides. I used to play online via wifi with very elaborate antenna arrays but it was not reliabe for gaming even though it worked. Upstairs I have another gaming rig via ethernet and the only difference between that and powerline is the higher download speed of ethernet. I notice no extra lag/latency. When I do speedtest my latency is 10-12ms via powerline.
I have two separate circuits next to each other and one has a UPC huge with surge suppressor. My powerline has it's own wallplate with just the powerline and the next circuit over has all my computer gear plugged into the UPC surge suppressor. Above the computer is the circuit breaker to the house.