Juan,
I really appreciate your input. I guess the best thing for color balance is just neutralize the background and let all the other colors fall into place. Right?
Perhaps, the G2V calibration is more of a way to find the required "filter factor" rather than to balance the colors. In other words, the G2V calculation provides a means to match a common S/N ratio across our filter set. Of course, there are still issues with the process, but one must have some way of gathering the proper signal for each color channel.
Wade