Remember that people's experiences with certain growing mixes also relate to their growing conditions.
As far as lfs as a medium, here is what the Mansells from Exotica say.
"We use both our commercial bark based medium and pure Long Stranded Sphagnum moss with good success. If we had to recommend one we would always choose the sphagnum moss. This gives us not only good success in growing the plants but it is also a good indicator of the plant's environment. In a lot of cases the highland species of Nepenthes grow naturally in live sphagnum moss so when the moss starts growing in our cultivation houses this is a good sign that the conditions are correct. Both the lowland and highland species grow well in Sphagnum moss. The only problem I have heard with regards to growing in Sphagnum is the tendency for it to slime up and break down quickly in areas where the water contains some minerals. A simple but effective way to overcome this is to cover the top of the pot with a layer of bark or similar material."
This question is relative. It varies from species to species. While I use at least some sphagnum in my Nep mix, I've moved away from it for stuff that likes it a bit drier (i.e. merrilliana, sumatrana, veitchii, etc.). I use mostly sphagnum, and sometimes even peat, for the ones that like more water (mirabilis, bicalcarata, ampullaria, alata, etc.).
Good point, Manny. Some of those you mentioned that like more water are actually grown by some using the tray method.
So, sumatrana likes a drier medium in your experience? Mine is still in the original Malesiana pot with lfs. It needs to be repotted...
Hi Joe. The Neps I grow in full sun next to my Sarrs actually sit in trays (the Sarrs do not, by the way). These are: khasiana, several forms of alata, mrabilis x khasiana, emmarene, and alata x maxima. Sumatrana, I've noticed (and have been informed), does indeed like it drier and shadier.