I am experiencing a sort of bug with the simplification function in the latest promo build (1.0.2.2600).
Note how in the attached screenshot model 5 and 6 still shows as having 10 parts?
That is with “Preserve Parts” set to “FALSE”.
RC does not combine the mesh parts into a single part and thus does not honour the above mentioned option.
Even a massive decimation to just a few 10k tris still retains the different parts.