Most likely that there is. Your wireless will almost always have more latency. You might not be able to tell the difference, but if someone else pings your console when it's in and out of WiFi you should be able to measure the difference. You're still probably less than 100 ms on the WiFi if you can't tell the difference, but hard connection will be marginally to greatly faster depending on the quality of your wireless. If for some reason your setup is the exception to the rule, I have no idea. But for most others thus will not be the case :)