I agree! I have the same "problem". But it only slow-down my system during i change into the edit-mode, or if i select my model. Without selecting or changing into edit-mode it runs perfect.
Keep in mind -> you can also sculpt in blender without selecting the object.
So the framerate keeps the green area.

I am afraid my laptop isn't able to edit my streetpolice-model. I think a systemcrash will follow soon.....