However, the built-in wifi chipset doesn't do channel hopping properly while the AR9331 does, meaning that for people doing 802.11 security stuff this is not the chipset for you.
If on the other hand you're not doing 802.11 or anything funky with the hardware, it's a nice little box. I have one using a CDC ether USB gadget to inject rickrolls into web pages.
Interesting. Did you do much hardware-wise for that - like rewire USB D+/D- signals and add/remove some obscure resistor that enables USB gadget mode?
EDIT: Actually there are quite a few boxes out there that do have CDC support built in. The ASUS WL-330NUL uses a stripped down ASUSWRT and has CDC support built-in. You can get the firmware source and build your own version if you like. It's not as friendly as OpenWRT (which is saying something) but is workable if you persevere.
http://wiki.openwrt.org/toh/unbranded/a5-v11