Well Worth the Upgrade
Setup is very easy. There are two network options, Ad-hoc and Infrastructure. The manual suggests that Ad-hoc is for peer-to-peer networking and Infrastructure for server networks but in fact I found that both options connected to an existing hub network.

Client configuration is a typical Wizard asking for Access Point Name, SSID, and channel number with the addition of a hexadecimal key if you choose the Infrastructure option. When you have filled in the details demanded by the Wizard, you reboot your computer and place the card in the laptop's PCI slot. Windows identifies the card and may ask for your Operating System Disk to complete the installation. Once the system setup is finished you are ready to go. An icon will be found on the task bar to access the configuration program if required. If you uninstall the product you may find that a locked file remains after running the Uninstall Wizard. If this occurs you will not be able to re-install the client and driver until you reboot and remove the remnants of the client program using Control Panel.

Overall the product works well and connected without any problems to both an 802.11b and 802.11g networks. Type G obviously offers extra speed and in every day working is similar to using a 100 MB wired network.

Did not work with Compaq/HP and WINXP (until BETA DRIVERs!)
As already mentioned by other reviewers, this card does not work on my Compaq Presario 900 running WinXP. The laptop freezes with 100% CPU utilization as soon as the card is installed. I've tried all the suggestions ranging from the latest drivers, disabling various items in the device manager and configuring WinXP zero config. wireless service. All to no avail! Customer support was sub-par, with the representative basically reading off a script. If you own a Compaq or HP laptop, please save yourself the trouble and DO NOT buy this until someone releases a fix!

!!UPDATE 4/1/03!!: This is no April Fools, Linksys has released a beta driver that did work for my Presario laptop. It can be found on their driver download page. In small print it says: "If you are having problems using this Adapter and you have a Texas Instrument CardBus Controller, please download this driver here."
I needed to install the driver in safe mode, but now it's smooth surfing!

Much faster!
Well this is a definite improvement in speed over the old 802.11 cards. It was a cinch to set up and seems to hold a better and stronger connection. Definitely a good deal!