Don't know about the skimz. I see it uses an aqualifter pump for the siphon. I was looking at the CPR overflow which also needs an aqualifter when I was looking, but was hesitant because it needed the pump for the siphon, if the pump failed it would break the siphon and the fact that I needed another outlet for the pump, which I didn't have and didn't want to add another wire to the mess that was already there made me go with the Eshopps. I figured I'd try the Eshopps and if I didn't like it would get the CPR. Well, after almost 2 years with the Eshopps I see no reason to switch.
Quietness is important to you so I couldn't tell you how quiet the skimz would be. The Eshopps right out of the box isn't quiet, a Stockman Standpipe is a must, but once you get that fixed it's very quiet. I have my tank next to my Den so it needed to be quiet for watching TV. Once I got the Stockman installed it stopped the gurgling slurping sound from the overflow and the only sound I hear now is the very faint sound of the water going down the drain hose.