The industry is discovering that CRI is not the best metric for comparing LED light sources, especially at Mesopic levels.  Originally developed in 1964, this index is based on outdated color models and assumes illumination sources with broad spectral distributions, whereas LEDs are narrow-band sources.  Nighttime lighting requirements fall primarily in the Mesopic range where our color sensitivity shifts with luminance, and there is no defined index.  The NIST is addressing this deficiency, and in the interim, Color Temperature may be the most suitable tool for comparison because it is independent of observer subjectivity.    NIST Invitation: Color Rendering Metric for Solid-State Lighting