It depends on so many things we can't have an answer for you.
one thing is for sure, Wired will not be slower than Wi-Fi.... but it may not be enough of an advantage in speed and reliability to be worth the extra cost or extra hassle of the wires. (but then the extra hassle of wires will vary massivly between every house and person too.... For me to have a wired connection to the Wii would involve a long wire and a hole drilled in my wall, plus pulling carpets up and moving everything to get the wire to my room... or to avoid drilling a hole in the wall a really long (10m+) wire going out into the hallway and back into my room... which would involve cutting a place for the wire to go under 3 different carpets and going through 2 doors (with the gripping plate between the doors needing cutting)
Luckily I have a pretty good throughput for my wireless it seems. On occasion the iPlayer has had to stop and load unfortunately, but it's rare.
