I'd avoid them myself. But I'd avoid wireless even more, so if you can't have wired LAN, then powerline may be the lesser of evils compared with wireless.
One thing to observe... the instructions will probably say not to use them on extension sockets, but may be vague as to what they mean by it. In fact, they depend upon the solid core mains wiring, so they need to be plugged directly into a wall socket. Plugging them into a trailing extension socket may seriously compromise their performance.