This is true it wont find overlapping faces and stuff like that but it will find all the open faces. Most of the errors people get will be open faces because the face wasnt created right or was or they just forgot a small one. It will show missing faces.I would always use stl for a error check fix any problems it shows and then export and run tool. Once thats done if you get errors import the wrl file into max. Then delete the face giving you the problem and remake it. Some times its just a edge acting weird and you will have to delete the edge.