Tested on dell xps l501x with backtrack 5 R2.
Really cheap usb adapter with 4.2 dbi detachable antenna. (Great with outdoor antennas)
Checked with :
Aireplay-ng -9 wlan1
Returns injection is working
txpower up to 30dbm
iw reg set BO
iwconfig wlan1 txpower 30dbm

Reaver -i mon0 -v -b [BSSID] --no-nacks is worki

So far I'm having great results with it.