I use one of the Monster AV strips mainly because it looks nice and is well made, plus I got a decent price on it. I like the convenience of having a single switch to disconnect everything from the power when I go out of town. I did not hear an audible difference between this and a $5 power strip.
A couple months ago I installed a dedicated 20 Amp outlet in my listening room. I could not hear an audible difference. Of course, I wasn't really expecting one. I installed the new outlet mainly because the electrician who intalled the original wiring was a retarded ape. All the kitchen outlets, utility room outlets, my listening room and a couple rec room outlets were on the same 15 Amp circuit. So if the refridgerator was running, if almost anything else started up - like the microwave, or dehumidifier, or coffee maker - there was a good chance of blowing the circuit. I had a (new) electrician come to install a couple of new lines anyhow, and he gave me a good price to add a line for my hifi.