Seems there are many variables to a no biological media system that would have to be taken into consideration before we made the determination that its not needed:
Planted/not planted/lightly planted
Livestock density- stocking density with 2 prior considerations in mind.
Livestock sensitivity- in combination with previous 3.
Agreed. I would never consider my current no-biomedia setup in a non-planted tank. It's absolutely critical, with a heavy fish load, to have a good and healthy plant mass if attempting no-biomedia in a tank with pH greater than 7.
Additionally, if anyone is considering moving to no-biomedia, do it slowly, over several weeks, to allow both plants and biofilm to adapt slowly to the change. Last thing you want to do is to kick things out of balance due to sudden changes. When I converted, I reduced my biomedia by about 20% of the original load every week. Obviously, that took me five weeks.