Planet Studio Tut Ep 6

Here's my explanation about the subbiome types (only briefly mentioned in the video):
Value-Based: The default type, this takes data ranges (from a noise or other source) and defines the subbiomes by that. Essentially, it works the same as the value based biomes seen in the video. These are generally the most frequently used. It has a singular input plug for the variance.
Height Based: This defines subbiome data purely by the elevation above sea level and nothing else. It can be easier to use than value based, but differs with players. It's simple and is generally used for simpler planets. An example of this subbiome type is the one in the "Taiga" biome in the Terrestrial/Droo-style template. It has a single input plug for the height variance.
Single: This one defines a singlular biome color and texture, with no changes and affects the whole biome. This is useful if the biomes themselves are already established by a noise in the biome pass. This is used in the Ocean floor biome in the Ocean/Nebra-based template, or the poles in the Martian/Cylero-based template. It has no input or output plugs.