The big guys may not offer the customization you get from a local craftsman, but factory-made-to-order cabinets have the following benefits:

1. Warranties of up to 25 years on cabinets, accessories, workmanship, and internal hardware.   
2. Controlled environment that yields more stable wood, which reduces warping and splitting later.
3. Computerized cutting tools that offer more precise joinery than anything done by hand.
4. Baked-on finishes that are more durable than local guys' air-dried ones. Dust-free finishing rooms also provide a smooth-as-glass surface.

Source material from http://www.thisoldhouse.com