600w = 2046 BTU regardless of the sourceI had better luck with hps indoors. It's a lot cheaper to get 600w of hps than 600w of good quality led. Also, the heat generated from hps goes towards heating the house.
But here electricity is dirt cheap.
For £15 its a working light, that sj reflector would cost 2x+ alone.That reflector is a load of crp man
There's a secret jardin parabolic your man of migro has a video on it
I'd recommend that cause it's a lighter material the other 1s are big heavy things