Why a Type per Phylum?

A fundamental choice is between a node type per phylum, as is done in Kimwitu, or a generic node type (the term structure to describe all term structures). This difference is comparable to that between compiled code and interpreted code. The first representation option is more efficient to use, it seems, but results in much more C-code (it might be different if assembly is generated directly). The second option is more suitable for language independent or polymorphic operations (as is used in the kernel of the Synthesizer Generator). An additional benefit of the first option is that it allows compile-time type checking of user-added code, as each phylum will correspond to a different type.