WiFi... every upgrade I've done since Lion has caused me pain. Upgrade, and WiFi stops working reliably. Last time was on a virtually new MacBook Pro, upgrading

WiFi... every upgrade I've done since Lion has caused me pain. Upgrade, and WiFi stops working reliably. Last time was on a virtually new MacBook Pro, upgrading to Mavericks, and it took me two weeks to get it working again. So I'm kind of wary of the 'wireless everything', which would be great if the wireless was working solidly in the first place.