Personally I've run CAT5 when I've added sockets or rewired after moving in. I've yet to own a house, esecially older, that's not been greatly lacking enough so

Personally I've run CAT5 when I've added sockets or rewired after moving in. I've yet to own a house, esecially older, that's not been greatly lacking enough sockets and I don't want everything hanging off an 8 way adaptor. With wood floors you can usually avoid much impact and just run cables under the floorboards.