The ATI remote is radio frequency operated, (not IR) and fairly easy to use. If you plan on using the ATI AIW media center to watch movies, etc, you might as well stick with the ATI remote for free. If you are like me, and only used you AIW card to record shows, and use Windows media player to actually watch them, you might want to consider the Media Center remote, which probably has ways to control more windows functions than the AIW. (Although I don't say that with authority.)
As an owner of two AIW cards in the past, let me give you one piece of unsolicited advice: Familiarize yourself with how to remove and reload ATI drivers. And don't update drivers unless you are having a serious problem with the card. Half the time, updating the drivers makes the problem worse.
When they work, the AIW cards are pretty slick...

Good Luck!