VectorBITS

VectorBits most sophisticated plug-in is OptimizeDrawing.  It is designed specifically to save many hours of hard cleanup with imported and complex drawings by allowing the removal of duplicated objects, joining overlapped lines and arcs, purging polygons, and automatically composing connected objects to form polygons or polylines.

2015 version is amazingly fast, and adds a dialog showing detailed information of all the optimization performed in the drawing. You will get cleaner geometry, and smaller documents that will redraw faster.

Optimize Drawing 2022 Demo