Yeah they do seem to need some filtered sun, and alot of water. If they hadn't come back from the stem, I wouldn't have been nearly as happy overall with this plant, cause they are kinda slow. I'm pretty sure some smaller tissue culture company is doing them. I got these two off ebay, and I noticed that Brian Williams also has them occassionally. Maybe someone with "Plant Delights" is the one TCing them?
Here's the same two a year earlier in the same 15 gallon pot. Maybe they were stunted?
Here's how the leaf meets petiole. That's one way Musa balbisiana is identified, but M.thompsoni and, M.initerans both have the same leaf thing going on.