I"ve been totally satisfied with my Equi=tech wall cabinet. It's been in service about 8yr. now. There is a slight hum from the cabinet, but it's off in another room, well away from listening areas. I've got JPS Labs in-wall cable on dedicated runs into the rooms, splitting left and right side into Oyaide R1 and Furutech receptacles.
The electrical is dead quiet. I have a couple of 'dirty' lines in my room for lights, etc, and you can certainly tell when you use one of those.
+++1.
my Equi=tech 10WQ Wall Cabinet is now 4 years old and i'm similarly fully satisfied. I use 10 gauge Romex in-wall instead of the JPS that Bruce uses. all 10 of my outlets are the Furutech GTX-D (r) that replaced the Oyaide R-1's I had previously.
I have 9 'dirty' outlets around my room which allows for an easy A/B anytime and it's not close.