A05 is the final silicon for the Geforce 3, the beta boards that some site got a long time ago were A03, they had to do a few changes to increase stability(get the bugs out) and, as i here, the chip now overclocks better to.
I'm still waiting to get one over here in the U.K. as they have not yet been formally released🙁
P.S. I'd like to know what the image quality is like compared the your G450, as i have the G400