Just asking here...
You said the hc4 will outdo a traditional hps, 264µmol at 200w, so two of these would be 528 at 400w.
The link you posted says that traditional hps gives 618µmol at 400w.
This shows that on this comparison the hps outperforms the led!
BUT!!!! This is only the comparison of two lights! Different lights use different parts and give different results.
So unless you are talking about the difference between two specific lights there realy is no point trying to say which one is better in the general sense!
Then you have the other big debate between the two, canopy light penetration! But im defo not getting into that, not enough evidence and two many people with their own opinions rhat denounce anothers just because its not the same as theirs... ✌