I got myself one of the new colorchecker passports. This product has three different targets in a little make-up mirror format. There is a classic colorchecker that we all now and love, a large white balance target and a "creative enhancement target". The package also comes with a CD with software that allows you to create calibrated dng profiles for use in Lightroom and ACR. There is even a plugin that works straight from Lightroom that is very handy.
Figure: The colorchecker and the creative target in direct sunlight. I white balanced this image from the neutral patch on the creative target and created a DNG profile that is used to correct the image. The image looks almost identical to the real life colorchecker. On mouse over you will see the rendering using the Adobe Standard profile for this camera (A Nikon D300).
Above, by mousing over the image, one can see the results from me calibrating my main camera. There are clear differences in the rendering of a few of the patches and the overall image appears warmer in the calibrated image than in the standard profile version even though both raw renderings were white balanced on the same patch. This might have to do with the very harsh sunlight at the altitudes here. I get far better skin tone rendering using these new profiles generated from the colorchecker. You could do this before (and I have done it) using a standard colorchecker and DNG profile editor. Strangely enough there are small differences between the profiles generated by the two different methods. Something to check out. What's most important of a card like this is to be able to get an accurate white balance. An example is below. This is a shot in my son's room with light from several compact fluorescent bulbs. The walls are painted lightly blue and my camera just has an extremely hard time measuring white balance correctly. The below shows the shot with default settings in camera and in Lightroom and the mouseover shows the result of balancing using the grey card and using a calibrated profile (less important here).
Figure: my son using automatic white balance and grey card white balance (mouseover). Mouseover this link to see the same but with the Adobe standard profile.
His pajamas of course are deep blue, not muddy cyan. Needless to say that the image that used a greycard for white balance is far better. There is not that much difference between the standard profile and the calibrated profile and there it comes down to taste.
The creative target that is provided (see the right part of the top image) is very handy as it changes both temperature and tint instead of just temperature. I measured the white balance change and in the top row (little portrait icons) of white balance patches, each successive patch shifts the assumed white balance up by about 250K, while the tint shifts by approximately 6. In the landscape row, each successive patch shifts by about 300K, while the tint shifts by about 7.5. You can do the same thing with the white balance quick adjust in Lightroom, but that shifts with larger steps and does not bring the tint along. The creative target on the passport is clearly well thought out in my opinion.
In conclusion, it is clear that using a correct color balance is very important especially in difficult light. You can use the colorchecker to very easily generate calibrated profiles for your camera which can significantly alter your image's appearance in limited circumstances.