Of course, cable is more reliable and can stand in front of big speeds.The matter with the wireless is that you can carry your pc/laptop in any place of your house (let's say) and have internet.Usually the speed depends on the quality of the router.In some cases the speed is decreased rapidly with wireless function.Although, I have LinkSys WAG200 and wireless it's just 1mb less than cable.So I think you won't understand any difference.You could post here the type of your connection (ISP) and your router type.I would be able to give you more info on this.
Awaiting a reply,
-Blane