Yea, I'm not sure about before Autodesk bought 3dsmax, but I know since they purchased the product, it has included native DWG import/export capabilities. It actually has several options to control the quality of the import, including keeping objects on proper layers, being able to assign materials by those layers, and being able to control the welding/"facetres" (forget the term 3dsmax uses) when you import. I found that when bring in a project of an offshore platform including all structural, mechanical and piping layers which totalled around 130 or so, I'd guess, the import and subsequent work was very easy to handle.