Which do you have Cat 5 or 5e, you mention both? Cat 5 is susceptible to crosstalk 5e not so much. If it's Cat 5 your wifi might sound better, 5e I would check connections etc... I have Cat6 (compareable to 5e) never noticed a difference except for occasional dropout with wifi.
Ethernet cable question
OK, at the risk of starting a big debate, I have just a dumb question: I see a lot of post talking about Supra 8 and Wireworld ethernet cables, so are you talking about cables making a direct run from your router? I have Cat 5 run throughout my house by me when our home was built 8 years ago. Everything is finished in the home and my sound room is not real close to where I have my network router/modem. So does the ethernet cable going from the wall to my Node 2i make any difference if inside the wall is only Cat5e?