I think the Black Dog gets just mediocre reviews. The area 51's get very good reviews. I'd say you can definitely grow 2 plants and get 2 oz a piece with this lamp. From the research I did a while back Area 51 was the best light I could find and the price was very reasonable. I see the new lights are using 10w Cree's. That's pretty interesting. http://a51led.com/store/index.php?main_page=product_info&cPath=65&products_id=192
You can do better for that money. There is an Area51 thread (<<link) where I and others posted pictures. If you really want to spend the kind of money Blackdog charges you could buy Apache Tech.
IMO, Blackdog, Kind, HydroGrowLED are just rebranded Chinese imports sold at a premium with a lot of hype about secret spectrum, etc. Area51 tells you the actual part numbers of the LEDs used.
IMO I BELIEVE the only side by side (LED vs HPS) was one blackdog did.
The video stated same strain, pheno, feeding everything. The only differance was one was under a 1000w hps, and the other was under like a 884w LED(or something close to that). The LED did grow a more robust plant!
I would just grow one monster tree in a 5-7 gallon bucket under the micro black dog. Only a 2.5 sq. ft. coverage on that baby. You really have to step to thier next light to cover two large plants not starving for additional light.