The images on the Seitz website are pretty representative. Color artifacts are there especially in transitions from extreme shadow to extreme highlights. They can be removed somewhat effectively with the Seitz processing software and CS4. They typically show up in reflections in water. But the shadows and skies are clean and color is very good. So, in sum, if you pixel peep a file from this camera against a p45 file, your will notice less sharpness and more noise.
But the point of this camera is that you do not have to pixel peep, because you do not need to enlarge as much. Printed at 240dpi, a Seitz file gives you a 90x250 print, which is about as big as I can print on the 9900 or would want to. It is an awesome sight to behold. Again, format is a big factor is the way these prints impress.
When you view the Seitz and p45 prints side by side enlarged to their normal viewing size, the Seitz prints have an ethereal quality that can be described as large format (in the traditional sense) where p45 files would be medium format. Like with film the sheer volume of additional information makes us perceive the image as having better tonality and depth.
I have not seen Better Light files; for me a 10min wait in the field for each image rules out this option. I would rather fiddle with stitching.