Keep in mind that a lot of the coral we grow van live 50 or 100 feet underwater, where they're not getting anything like the kind of light they would in a typical SPS tank. They probably rely more heavily on suspended food, and/or grow more slowly. Also, given that the pigments we like in corals are usually some form of UV protection, lower light corals might be expected to be less colorful than heavily lit ones would be.
The high light approach is aimed at growing corals quickly, and with a high success rate, but a skilled aquarist can take advantage of the natural adaptability of corals to fill in weak spots (low light) in the overall approach.
Mr. Gonzo has also shown the all too often ignored lesson that more and better equipment doesn't guarantee success, and the lack thereof doesn't guarantee failure. A lesson I need to be reminded of from time to time.
All of that said, I think the stock biocube filter pads are at best passable, and given some research, you can come up with better products to fill that space for less money.
I'm using some seachem matrix, a bag of chemipure, and some cheap rolled filter pad stuff that I can replace every day. For the stuff I use, replacing the pad every day will cost like $3.25 a month, and should work pretty well for nutrient export alongside weekly small water changes. (Those two things are in place of a skimmer)