Got Zyxel powerlines at home and its somewhat good, it all depends on your house wireing. If your house got old wires then it might just give you awful speed. Why not just get a wifi AP and extend your signal from your router? If I compare my wifi setup with my last powerline setup the latency was always better on the powerline, but the speed of the transfere was slightly higher on the wifi, but it all dependes how much interference was is the air at the time.
It all depends on what your gonna do, lots of filetransfer I recommend doing a network cable from the router(its always the best if its an option). Gaming and surfing I would say powerline because of the more constant latencies.
Linus got a good movie showing you powerline VS wifi check it out.
best regards
/D-tail