While comparing the features of Canon 400D and 1000D, I've noticed that Canon 1000D has an improved DIGIC III processor, over the DIGIC II for Canon 400D.
The DIGIC III Image Processor was advertised to deliver superior image quality, faster operation and extended battery life compared to its predecessor.
Will a newer version of the DIGIC processor provide visible improvements of image quality? What about when shooting in RAW?
I understand that newer versions may perform faster (when focusing, or a higher frame rate) and have features such as face detection and live view, but that is of no importance to me.