I have no regrets with the Quattron. Compared to the tri-color, the fleshtones and black and white are more consistent.
The yellow pixel allows a deeper green to be used because the green doesn't have to span the entire center of the spectrum.
Whether the yellow pixel is put to full use is another question as is the LED backlight's tendency towards blue.
A much wider gamut could have been achieved with the 4 colors and a full-spectrum backlight. As it is, the red is anemic...