With my recent visit to Sigma local office, I've got the opportunity to review the flagship DSLR of Sigma - Sigma SD14. What differentiates this DSLR is the sensor type found in the camera. Unlike what every non-Sigma DSLR manufacturers use, Sigma acquired and uses the Foveon X3 image sensor that boasts 100% capability to capture ALL RGB color on each pixel of the sensor.
The Sigma SD14 catalog sample shots are astounding but are what I suspect, "touched-up" copy of the original photo with the Sigma Photo Pro 3.0 software. Makes me wonder how those Flickr images on the Internet orginally look like...average I would say.
Technically and theoretically, I believe the Foveon X3 is a superior technology, but realistically, Sigma just could not deliver a complete package, having the result marred with higher noise at high ISO. That aside, Foveon's low-light performance are seen superior to the Bayer-filter implementations.
Who knows? Maybe, with a proper lab, it can be perfected?