i second that. that close wired will give a more stable connection.
if you chose the wifi chose a card with an antenna on a cable so you can get it from behind the case or a usb stick on an extension cable for the same reason. even in the same room, hiding the antenna on the back of a case, under a desk, on the floor..... can hurt the performance of the adapter. get it up in the air some like you would any other radio antenna. it is a radio antenna and subject to interference and poor reception like any other radio antenna.