A fuge needs less light, but will host more good bugs . A reactor or turf scrubber
Needs more light and pulls out extra nutrients quicker. The more light usually you can decrease the footprint,because stuff grows quicker. The less light stuff grows slower, but you can keep increasing size to achieve similar results. I've ran a fuge cheato reactor and now a ATS. Those seem to be what I've found. I had a large fuge with a lot of algae I harvested and got similar, but slightly slower nutrient removal. I run both ow , as I need more good bugs plus need extra nutrient removal.
Nitrate usually comes down quicker than phosphate. If you get your nitrate to 0 it will limit your phosphate removal .
I didn't have good luck growing cheato in a cheato reactor but better luck growing turf algae in a scrubber. Some people have fifty results based on thier system.
HTH's
Todd