I can't speak towards NYOS, but they do have good ratings. I can only speak on my Reef Octopus 150SSS and the 250SSS that I have in my tank currently. I feel Reef Octopus underrate their skimmers. I feel they can handle more that what is rated. I had a 150SSS on my 120 gal tank and felt it could work on a 150. I have a 250SSS on my 225 and it is working flawlessly, even when I may have oversized the skimmer. The point is, with Reef Octopus skimmers, the amount of flexibility when dialing it is well worth buying them.