With all my cards, 3Com has either kept the same chipset/drivers, or created slightly different models. In my house I have a 3c905, 3c905b and a 3c905c. And a few others (Like an ancient ISA card in my Linux box). The one complaint I could possibly have with the 3Com products was lack of Pocket PC drivers for their AirConnect cards early on. But they still had them out faster then most of the other cards at the time.