Obvously Wi-fi! There is no such thing as a problem, in my house we have a mucrowave, and 4 PCs using the same wi-fi, and there is absolutely no problem!
There are practically no cons to wi-fi, only pros.
(The only disadantage you may find is if you want to share files via the same local network, in that case a Gigabit Ethernet connection would be faster, but in that case, USB 3.0 would be even a lot faster...)