I have a PRO/100B that I bought used off of an auction site. I've been really happy with it. It uses the same drivers as the newer PRO/100+ and PRO/100 S, so you get fairly frequent updates and also the PROSet utility. I've had no problems using mine in Windows 2000, Linux (use the eepro100 driver), FreeBSD, and even BeOS. Plus, it has a lifetime warranty. I would definitely recommend this card.