Took a quick turn around Plantgeek and didn't find the post you were referring to but no problem. Plantgeek is an excellent plant source but as everywhere else opinions vary.
The experience I had with epoxy coated gravel was that the epoxy peeled off in my tank. I don't know of anyone else who had that experience

Plants will grow in just about any substrate to greater or lesser degree. I use peagravel and sand and have plants. I usually put plant tabs under the heavier feeders because there isn't anything in the gravel except fish poo to help them grow. Since my lights are low I use low light plants.
So really your substrate depends on what you want to grow, and opinions and experience differs on the various substrates available.
Carol