Check out the se-450 by Amare. Cree 3070 cobs and Cree monochromes surrounding the cobs. Besides efficiency this panel is built so nice. Aluminum frame and even stainless steel hardware. The warranty is 5 years and the owner is brilliant. Quick to reply with all data needed and friendly as can beIf the data is accurate on their site it doesn't look too bad.
660w for a ppfd of 909. To compare an unreflected 1000w Hortilux eye is 1798. Based on their numbers, they're running ~35% efficiency. Better spread plays a large part, but the light itself is less efficient than HPS.(42%)