From advanced Aquarist, its a very long article.
Conclusions
Many factors contribute to the "value" of a skimmer to an aquarist, including quality of construction, size, footprint, noise level, ease of cleaning, energy efficiency of the pump, and of course, the ability to remove organic waste from aquarium water. Our data show that there are not compelling or remarkably large differences in measurable skimmer TOC removal metrics among the seven skimmers tested, although the Reef Octopus 150 consistently underperformed compared to the other skimmers. However, in the larger picture, it is equally apparent that if an aquarist runs a skimmer continuously (24/7), then any of the skimmers tested would perform adequately in terms of rate of TOC removal; the only practical differences might involve the frequency of skimmer cup cleaning. A perhaps more interesting observation to emerge from these skimmer studies involves not the rate of TOC removal, but rather the amount of TOC removed. None of the skimmers tested removed more than 35% of the extant TOC, leading to the conclusion that bubbles are really not a very effective medium for organic nutrient removal.
I really cannot defend my statement below however based on what I read :
If a skimmer only removes up to 20~35% of TOC from your aquarium getting a better skimmer only marginally improves the overall result which in fact may not have a measurable change, even if you end up changing the skimmer cup more frequently..... Could there be better places to spend our money.. ?