Have used this in Dell C610s, D600s, Thinkpad T-23 without a hitch. The intel proset utility works great - so much better than using the Dell or IBM wireless utility. The profiles you create for authentication can be exported between users (different userids on the same laptop) - or may be exported than imported into another laptop using the same card (nice if you have several laptops to configure with WPA or LEAP).
The proset utility will do CISCO LEAP - however - it is not aware of the windows logged in credentials, you have to manually enter them one time and save it. Not a big deal.
Better performance in the Dells than the following cards I have used: Dell 1150, Dell 1300, Dell 1350 (although the 1350 is close I would say).
Works great with the 802.11b and g rates. Cisco, zyxel, netgear and D-link access points without a problem. WEP, WPA, Leap, radius all work flawlessly.
If you have this card - remember to let the proset utility manage the wireless connection, not windows.