I've heard great things. The w is better for shallower tanks, less that 24" I think. These give the most realistic shimmer imho that looks like a mh bulb because the 1 large optic and the way all the colors are mixed. You can control the blue and white separately but I think they only have 1 power cord. That makes the dawn dusk thing a bit more complicated. Great option for efficient and low profile contemporary look light.