You most likely have 54mbs wireless connection. Your actual internet speed is no where even close to that fast most likely between 3-7mbs. So I say you would see no speed difference. However there may be a reliability difference. A wired connection is always more reliable than a wireless connection. Wireless can be prone to interference and dropped or degraded connections.
Wired will and should be more reliable for speed, as wireless can fluctuate. Simple browsing you may not notice large differences with the exception of large downloads (i.e large images from websites).
If you are a downloader/game player, wired is much better.
Wired is 100Mb or 1000Mb depending on your equipment, most likely 100. So transfering PCs that are networked and connected via patch cables to the router will be at least twice the speed of your wireless.