I think eco-complete is about the same as azoo plant grower bed. What i don't like about it is that if i stir just a little bit the substrate a cloud of dust and debris rises and takes a while to settle... on the plants! And if i stir the plants the debris rises again and settles again on the plants, very annoying and frustrating.
I've read this article
http://www.plantedtank.net/articles/Sand-Substrate/20/ and thought of using sand/flourite, but instead of layering i thought of mixing the sand with the flourite, so as not exposing too much the flourite and preventing the sand from compacting around the plant roots.