I have read that many Nepanthes do well in pure long sphagnum moss. I just got a couple tiny plants and am thinking about trying it. My other plants are in a peat/sand mix with some live moss on top. Is anyone growing theirs this way? I also have some fir bark (reptile bark) and am thinking about mixing that in as well. An experiment to see if I get bigger plants than what I have now.
Mine came in sphagnum so I put that into a pot and added shredded coconut husk to fill in the gaps. The sphagnum hasn't survived so I'll top up with more coconut husk and probably add a bit of sand. Checking out habitat information, it apparently comes from swamps where its roots are sometimes in submerged soil. I think it's important to know about habitat so you can imitate as close as possible. Experimenting is good though, if you've got spare plants.
I have done long fibered sphagnum with success. I actually have several nepenthes in LFS including N. hamata, N. ventricosa had an N. jamban that way but it died recently :(
Personally, I do not use LFS anymore and have been switching substrates. I much prefer an airy mix now.