how come when i import a dxf, it always has THOUSANDS of vertex doubles???

Well, if you really want to know… It appears that the DXF-format prefers to describe every polygon as a three dimensional entity, that is with a certain thickness. So if you build a cube in a standard 3D application you will only need to define 8 vertices and the resulting 6 faces. There are no doubles there. But if you save this to DXF, the shape will also get an additional 8 vertices inside the cube in order to describe the fact that each of those 6 faces actually have a thickness, although that thickness is infinitely small, but existant nontheless.

I guess this comes from the background in CAD that DXF has. If you model stuff that will eventually be real physical objects, you’re not likely to see anything manufactured from a piece of sheet metal for instance, with a thickness of zero millimeters. Every real object is 3D (height, width and depth) even if it’s just a polygon.

Are we clear on that!?

Edit: maybe you could include this @ BlenTips