If you are still working with traditional Gerber formats from other systems, then you'll be pleased to find that VisualCAM includes an Import Wizard that goes beyond just importing Gerber data. Using the Import Wizard, you simply direct VisualCAM to the location of your data, and it does the rest by detecting the various file formats (Gerber, Drill, Mill, HPGL, DXF, etc.) automatically. If you still use 274D, it will even detect aperture table formats and convert them as well. VisualCAM also has format-specific interfaces for all supported database types (Gerber, Barco DPF, DXF, HPGL & HPGL/2, Excellon, Sieb & Meyer, IPC-D-356A, etc.), just in case you want to load a single file or re-load existing files.
These are only a few features.