C. David Tobie, of Data Color (color calibration tools) reviewed the riMac and said:
You can read the first part of his review at http://blog.datacolor.com/c-david-tobie-the-retina-imac-for-photo-and-video-work-part-i/
Part II has specifics relative to color; it's at http://blog.datacolor.com/c-david-tobie-the-retina-imac-for-photo-and-video-work-part-ii/
The clear answer is that the Retina iMac is unquestionably the best still image edting system available, and a steal at the price.
You can read the first part of his review at http://blog.datacolor.com/c-david-tobie-the-retina-imac-for-photo-and-video-work-part-i/
Part II has specifics relative to color; it's at http://blog.datacolor.com/c-david-tobie-the-retina-imac-for-photo-and-video-work-part-ii/