I'm using the previous Monster power center, 2500mkii ($110 refurbed). It works fine for surge protection. As far as sound and picture qualities go, I couldn't tell any difference at all between before and after. Maybe i'm not 'sensitive' enough or maybe there's no noticeable difference. I don't recall having 'noise' in either sound or picture prior to using it, so I really can't say either way.
The one thing I don't like is the plugs do not sit securely in the back of the unit. They are not falling out, but they do hang out enough to show its definately not a snug fit. I believe there was a nice review of it on this site a few years back, might be worth checking the reviews section of the main page.
Jack