I have a retina MacBook Pro 15" running Mac OS X 10.9.1. When I wake it from sleep at work, it's connected to the wifi network before I've even entered my password. But at home, with a Airport Extreme base station from about 2009, it takes 30 seconds at minimum every time I wake from sleep, and sometimes up to a couple minutes.
I've tried rebooting the Airport Extreme, it doesn't need any firmware updates, and of course the laptop itself has been rebooted many times since this problem all started (months ago). I'm sitting in the same room with the thing, so the signal power should be great - not to mention my iOS devices (and other Macs) have no problems connecting instantly to the Airport. So it seems like it's got to be a local computer problem, but then why do I have no problem instantly connecting to other wifi networks?