I have not used too many substrates actually. The EcoComplete that Luis put in that tank was very much agains my will because I don't like the pH buffering and the KH/GH (exclusively Ca and no Mg) increase that that substrate adds.
But honestly what I see with EcoComplete are some very deep glosso roots. That can't be bad
Anything special with this setup.. The glosso grows very dense and very low, but I have 4.4 wpg over that tank. Also the substrate may be responsible for a lot of nutrients because the plants bubble extremely heavy even if I don't fertilize for days.