Randy I'm running wall plates for everything, six sub outlet plates, eight speaker plates and all of my interconnects without fear of any loss of sound/visual quality.
Be careful about running your power cables alongside your other cables, you *may* get interference which may be far worse than using wall plates. I have two places where my speaker or interconnect cables get close to the 12/2 Romex inside of the attic. I made sure the Romex crossed the other cables at 90 degrees and then wrapped both sets of cables with thick foam insulation to keep as maximum distance as possible. Throughout this project my pet peeve has been keeping all power cables maximum distance from speaker and interconnect cables.
