I live in a semi detached house where all the wall sockets in the house are on the same ring main and I heard that different sockets may give you different speedRunning a cable is preferable, but assuming both are on the same ring main then it basically comes down to how fast you want that link to be. Remember power line claimed speeds tend to be a combined up/down figure so 200mbit power line is 100mbit each way max. I can comfortably stream h264 BD rips over 200mbit power line plugs, but wiring condition and things like being on a spur from another socket and extension/surge suppression all can reduce maximum bandwidth.