IMHO algae scrubbing works, but a berlin type sump with a large, powerful skimmer and optionally a refugium works better.
I ran my system for a number of years using algae scrubbing. I found that nitrates and phosphates did stay down, but since your growing algae in the scrubber it's also easy to grow unwanted algae in the tank. A good clean up crew will help keep this down.
I found that algae are leaky filters and the water can easily become tinted. This can be solved by using skimming and/or carbon filtration in addition to algae scrubbing.
I found the scrubber can act as a mechanical filter and trap dirt, even if you clean it regularly. The result is that until you clean the scrubber the dirt is still in the system. BTY this is true of most mechanical filters.
Perhaps the question here should be what are you considering doing with algae scrubbing?
If I was going to use it today, I would use it like a refugium is used. In other words, supply it with prefiltered water, and let the scrubber go from there. This solves a lot of the down side problems.