Any renderer has to be optimized for the task it's used for.
LDView is optimized for quality viewing, so it takes all the model data and compiles it into a single object so the VGA hardware can do it thing efficient.
Editors can't do that cause you will be moving parts, so they need to optimize on part level in order to find balance between rendering speed and quality.
L3Pub seems to do no optimizations (or very little) resulting in fast loading times (no mesh preparation etc) but slow rendering (drawing single triangles etc).
LDView is optimized for quality viewing, so it takes all the model data and compiles it into a single object so the VGA hardware can do it thing efficient.
Editors can't do that cause you will be moving parts, so they need to optimize on part level in order to find balance between rendering speed and quality.
L3Pub seems to do no optimizations (or very little) resulting in fast loading times (no mesh preparation etc) but slow rendering (drawing single triangles etc).