I know this is an old thread but I just wanted to add my favorite aspect of using a USB adapter is passing it to guest VM's. Can't share a cardbus adapter with a VM in VMware.

I've been using a trio of Ubiquiti SR71 adapters strapped to my Windows 7 tablet so I can continuously monitor 1,6,11 or trade up between monitor and master mode. They are a little pricey but deliver excellent range, are compatible with BT4 with minimal effort and work quite nicely with my Airmagnet tools.

http://www.wlanparts.com/product/SR71-USB/Ubiquiti-Networks-SR71-USB-WLAN-USB-80211abgn-MIMO.html

P.S. thanks Aranger for resurrecting this dead post so I didn't have to be the one