Had some time today to use the recently purchased Ubiquiti SR71-C with the ath9k drivers. Set up my "honeypot" Belkin b/g AP with a long WEP key and used Gerix-WiFi-Cracker's "ChopChop" . Everything worked, although the process seemed to be a little fussy at times. Don't know if it was the Belkin "honeypot" or the card. Having to make several "false AP authentications" before getting a "good" small packet to use for creating the ARP packet was the norm. Monitor mode and injection works.

Reconfigured the Belkin "honeypot" with WPA2-AES(only), injected a deauth after connecting to it with a WiFi card in my desktop, and immediately captured a WPA handshake. As the laptop doesn't have graphics that can fully leverage on Pyrit (with Cuda or ATi-Stream), it's taking a while to work the ESSID PMKs at about 350 per second.

The Belkin "honeypot" AP I use for testing is a cheapie b/g, so I wasn't able to make any runs against an 802.11n (only) system. May be able to do that in the next day or so using my meshed network spare "n" router . . . and set it up with "n-only" for some tests.

The results today, testing against a crappy b/g Belkin (usually runs as a "honeypot"), were surprising given what I had found about the SR71-C supposedly not supported by the ath9k drivers.

Bottom Line (for now):
The Ubiquiti SR71-C work in b/g.