immediate

pro: simple mental model
     draw directly from any data structure
     minimal state thus few caching issues
     compact code for many things
     can easily implement retained on top
con: not well explored, might
     be inspiration in displaypostscript, NeWS
     and in IMGUI which uses inline callbacks.

retained:

pro: well understood
     well suited for optimizations
     scales well
con: temporary object overhead
     cache-invalidation issues