Shawn,
Soil found in nature is very different from soil sold at the nursery. Not sure if it is the same in the other parts of the world but if we say "Neps can be grown in soil" here, what we are going to see is the bulk of the growers buying the brown/black soil from the nurseries. That soil is packed with animal manure!
Like Robert highlighted, the soil found in his garden is intertwined with roots of the trees which makes it very open and good for drainage. If we try and imitate that, without observing the presence of the roots, then we will end up potting up the Neps in pure clayey soil. That is detrimental to the plants. I cringed the last time someone on the forum made a very general statement that N. ampullaria grow in clayey soil. It is clear that that is knowledge gleaned from books or websites, without in-situ experience.
What Robert is doing, as well as others who spend their time in studying the plants in the wild, is to value-add and give the year-round city dwellers like us (myself included) a clearer picture of Nepenthes cultivation. If anyone has the chance to, please take a trip to any of the nature reserves and spend some time studying the plants there. It was very enriching for me and even caused a paradigm shift in my cultivation methods. I still cannot grow highland Neps for that matter but I am pretty sure I have better growing lowland/intermediate species than before.
