Better sound with ethernet cable?

I'm presently streaming music WIRELESS from my WiFi router to my Yamaha receiver.  I was told I would get better sound if I ran an ethernet cable. It's a fairly long run, maybe 50 feet total by the time I fish down through the basement and back up.  Before I drill holes and fish through the basement, I may just run it across my living room and see if it improves the sound.  Also, in my manual there are two different instruction for hooking up to wired or wireless. Can I just plug in the cable now or will I have to re-connect through the wired instructions?  Thanks for any input.  Doug