I've had the Reef Octopus NWB150 6” Pinwheel In Sump Protein Skimmer, since the beginning. I can't compare it with others, as it's the only one I've had, but I think it does a great job. Pulls out a lot of crap. It was very easy to dial in. The only downside was how loud it was initially, but you can make a DIY silencer with PVC
super easy and cheap. The other need-to-know is that it needs fairly consistent water depth. It will work well once dialed in, and also within plus or minus 1/2" of water and then it will start to overflow.