So, finally installed Win XP on the ASUS 2g surf after giving PfSense 2.0 a shot
And I have to say that the OEM drivers for Windows is much, much better than the run or urtw drivers for FreeBSD. It's too bad because I think PfSense is by far one of the coolest networking software I've ever used.
Anyways, if anyone is thinking of using PfSense to do a wireless to wireless bridged network using run or urtw drivers, I wouldn't recommend it. The driver's are pretty ghastly in terms of performance.
Finally, I was a bit surprised to see Windows XP, although chunking up lots of CPU usage compared to PfSense on the small Asus 2g, actually held its own in terms of battery performance. Both builds run approximately 2+ hours on an old battery. Pretty impressed.