I would say ranking skimmers borders on impossible. The different designs remove different compounds. We know our design is very strong at removing cellulose and capsaicin, it probably beats a lot of others at that. Big skimmers remove more proteins and then depending on contact time/ bubble size they remove different proteins. I have generally chosen Tunze because they work well enough and they are small and easy to use and consistent and quiet. To be honest thoough my only other skimmer experiences were the Berlin, Sanders air stone models (the bigger ones that were hang ons) and Euro Reefs and an Aqua C. The main thing I didn't like about those was they were inconsistent and tended to foam over periodically or require an adjustment but they could skim well enough, sometimes better. I just like all the comfort features.