I ran a CPR Aquafuge 2 gallon on my 46 reef. It grew cheato like crazy and I think worked like a champ. That said, I used it in conjunction with a really powerful HOB Deltc skimmer. As a side note, one design flaw of the CPR is the in-tank intake pump. I wrote to them 3 days ago and asked if they had plans to create a new design with an internal pump so that it was not visible with the display. This was their response....
"Hi! Thank you for the feedback. When we first designed the AquaFuge, we considered modifying the intake to be a draw in model, but over time, we found several issues that could arise with the pump inside of the unit. There were certainly pros and cons to the set up, but we decided at that point to arrange the pump as you see it today. We are always considering new upgrades and changes, so we will take your feedback seriously and appreciate you taking the time to contact us about this. Thanks so much for being a CPR customer!"
further...
"Thanks for the information and being a great member of the reef community. I will let you know that we are working on an LED light for our AquaFuges will will also include a couple other enhancements. They do not include the pump alteration as you suggested, but as I mentioned, we will keep that feedback in mind as we continue to develop. Thank you again!"
If you are going to entertain an HOB fuge, maybe ask them their time frame for release of their new models. Unfortunately it doesn't look like the infuge pump is going to fly anytime soon but still, I found it to be a solid product that seemed to help in my setup.
Good luck