Has anyone ever heard of Volt Lighting? They mostly make landscaping lighting but they have a couple of grow lights in their lineup.
After shopping the market for a while I decided to give them a shot, mostly because they have a 440 watt fixture on sale for $350. And they don't seem like the kind of company that's going to BS on specs - I have a feeling when I connect a Killawatt to it it's going to be right on the money.
VL-1 Full-Cycle LED Grow Light | VOLT® Lighting
It's a bit of a pig in a poke because I did a pretty thorough web search and was unable to find anyone who knew anything about them, let alone having completed a grow with them, so I'll be something of a beta tester. But it seems to have the right stuff: Samsung/Osram chipset, three levels of dimming control, huge aluminum heatsink, five-year warranty, and its footprint fills a 3x3 area very nicely.
Once I get it I plan on running some heat tests to see how much it warms the tent and how much airflow it takes to keep things cool. If anything is out of order I will take advantage of the 30 day no-restocking-fee return policy.