You never realize how bad the seaclone is until you see what happens with another skimmer. I made a DIY recirculating skimmer out of PVC for about $30 in parts, and used a MJ1200 (same as seaclone uses) for the recirculating pump.
I wanted to see what would happen so I left the seaclone on the tank and hooked up my DIY one. After about 1 day of both of them removing skimmate the seaclone stopped removing anything from the water. After 2 days the seaclone couldn't even make a bubble of foam in the tube. I left both running for 2 weeks. Every day the DIY pulled out 1/2 cup or so of dark skimmate and the seaclone could no longer pull out anything.
Even though my seaclone appeared like it was working alright before I added some competition to it, my test helps to show that the seaclone needs an already high level of organics to start to pull stuff out of the water. My DIY skimmer was able to lower the organics to a level where the seaclone was worthless and still pull out skimmate. My tank appeared healthier as well.