I have some plants in the 75g, but they just seem to be surviving rather than thriving. However, the substrate I have is a thin layer of Aqua Soil capped with an inch of Black Tahitian Sand. Since the grain is so fine, I'm not sure if that's affecting the root growth in the plants making it hard for them to grow or if it's the light. I've tried planting Amazon Swords, Dwarf Sag, and Crypts. And the only one still standing is the Crypt, but it's really not doing much. I also have Anubias and Java Fern in there which are doing okay. The Anubias use to have big foliage as big as my hands in the beginning and the new growth is probably no bigger than a 1" leaf now a days. And the Java Fern is just all loose and flying around the tank now as it never attached to anything.
My tank definitely needs to be rescaped, but compared to the other tanks, this seems to be the "worst" tank. Even the tank with PFS and T5HO are growing the same Crypts better.