LED is so cool compared to quartz but:

I have been using some LED lighting lately.  There are color spikes in the LED waveform so they may have more green or other colors than you expect.  These can be filtered out but it is kind of a pain.  The big problem i find with the LED lighting is the lack of a full color spectrum in the lights so that flesh tones are not rendered with the full gradiant of color which I prefer.  So I have been using the LEDs as hair rim lights and lights for set or background and soft quartz for the faces in the foreground.