I've run Phoenix, Radiums, XM, and Ushio's, but the best 150 watt DE 20k bulb I've ever had was the Aqualine Pro series. It's a whiter 20k, but the growth and colors of the corals it brought out was amazing. I bought it from a reefer who never used the bulb for $70, but new they're pretty pricey in the $100 range.
Next time I change out my 250 watt 14k Phoenix bulbs is going to be back to the Aqualine.