But XeTeX and LuaTeX are still billed as "end-user-facing" systems, alternatives to LaTeX and ConTeXt. I appreciate the distinction between the actual typesetti

But XeTeX and LuaTeX are still billed as "end-user-facing" systems, alternatives to LaTeX and ConTeXt. I appreciate the distinction between the actual typesetting engine and a macro library layered on top, but as someone who has only ever used LaTeX I would definitely be interested in a thorough comparison of their capabilities, speed, user experience, etc. One can of course include plain TeX itself in such a comparison!