I have one from Malesiana, in the little flimsy pot they ship it in that is starting to go into high gear. These guys like big pots, right? I suppose now would be a good time to cut away their little pot and lower it into a larger pot?
I love N. sumatrana but it does not seem like many people grow it. I have been growing N. sumatrana for a few years now and have always had it in very large pot right now the plant is about 23" inches and it is in a 8 1/2" wooden orchid basket. If you have the June 2000 issue of the of the CPNL they have a photo of a N. sumatrana growing in a small pot filled with an inorganic potting mix.
I do have that issue, lol. Seramis, Lectacon and lava pebbles in a black netted pot.