Were I in E-On place, I would make this subdivision:

xStream: everything, embedded in native modeling apps;
Infinite: xStream minus embedding;
Complete: Infinite minus Python scripting and (perhaps) minus advanced radiosity for internals.

Pros need scripting for creating their proprietary tools and therefore omitting scripting from Complete would make them not even consider anything below Infinite; the question for them would be very simple: Do I need embedding? if yes, xStream, if not, Infinte.

For everybodies else it would be a "picture collecting contest" to reach Complete.

Clean and fair.

Bye!!!

GIMP 2.7.4, Inkscape 0.48, Genetica 3.6 Basic, FilterForge 3 Professional, Blender 2.61, SketchUp 8, PoserPro 2012, Vue 10 Infinite, World Machine 2.3, GeoControl 2