Unless you can get a high end led, or build your own, you won't match the power of an HID.
Don't get me wrong, I think LED is the future. But I was running a Mars 2 1200 in a 4x4. It's not enough output to slay a 4x4. You will get a 2x2 spot of good growth. But to kill the entire tent, I had to start running hanging cfl's So with the 600 the Mars draws, & then the wattage of the CFL's, I'm using the same wattage as a 1kw, but not the same results.
It vegges well. But unless you have $700-$1000 to build a light, you will do better flowering with an HPS.
I plan to build an LED in a few months...& hopefully do a side by side with the HPS.
It's not a terrible light, but it doesn't replace a 1kw, not by a long stretch. I don't know why these LED companies insist on using that marketing strategy.
It also adds MORE heat to the tent than a cooled HID.