Go with VMware. I was going bonkers trying to make my USB wireless adapter work in a BT 5r3 VM run by VirtualBox, then was delighted when Kali came out, but disappointed when I had the same problem. I installed VMware Workstation and bingo, works automagically! Now I can use aircrack-ng, etc. with no problems. Just wanted to share this experience. In case you're pulling your hair out trying to get your USB wireless adapter working in a Kali VM run by VirtualBox. So it seems VMware's drivers are superior in this aspect.