The ONLY justification for a 'DESKTOP' with Wi-Fi is if your Wi-Fi is FREE. Otherwise, don't use Wi-Fi on any Desktop and instead use PowerLine (Receptacle based solution). Obviously, the best solution is a wired connection.
Wi-Fi is very slow, roller coaster bandwidth, high latency -- i.e. not good.
PowerLine vs Wi-Fi vs CAT-5/6:
[flash=640,480]http://www.youtube.com/v/Sue1Zvmh8JA[/flash]