As long as they stay 2D they are fine, but I've seen some weird anomalies when extruding them to 3D. DXF, though there are sometimes issues with its. Plus, I've been using Illustrator for about 12 years, so that alone makes things a lot easier. This would be especially good for the silkscreen layer, because in Illustrator I can match text exactly, even if I don't have the correct font. I really like this idea, because I can very accurately reproduce almost anything in Illustrator the drawing tools are far superior to anything you'd find integrated into a PCB design program drawing is Illustrator's specialty, and it's the de facto industry standard. During import, DipTrace let's you assign each DXF layer to something different (pads, top and bottom copper, silk, paste, etc.), which allowed me to have a fully editable version of the board that I could produce Gerbers from. (Be aware the import will flatten the image to black and white (not grayscale), so you might want to do that yourself in a image editor before hand.) Edit: Once I scanned an old PCB and separated the traces from pads into separate layers using my photo editor, then I ran the layers through an online raster to vector converter, took the resulting SVGs and converted them to a single multilayer DXF and imported it into DipTrace. So long as you crop and scale your image in a vector editor (GIMP/PhotoShop/Pixelmator) it should work fine. For raster images, DipTrace will also allow you to apply a BMP/PNG/JPEG as a Silk/Assembly/Paste/Copper layer. If you have a PDF file that contains a layout, you can use 'pstoedit' to convert it from PostScript to DXF.

DipTrace can import DXF and Gerber files.

Diptrace pattern editor import dxf