I haven't done the deal on the 600 yet. I wouldv'e today but my A/C hasn't been working for a while and it was uber hot today so I got it fixed this morning and went to the hydro shop to pick up another 2 foot 4 tube T5 H.O.
While I was there I saw something very interesting, he has two big LED fixtures for sale that are priced less than half of what I can find anything comparable. The smaller one said 575watt on it and I don't remember what the other was. He had a funny disclaimer on the signs he made up for them that said "great for supplemental lighting, no guaranteed results".
I'm still working on the wifey a bit before I go get the 600. I'm trying to get another 400 and double up in the flower room but if I can't convince her I'll get the 600 and replace the 400 with it. She's just not sold on doubling the power usage, you know? The way I see it, I could almost run a 1000 for what it will cost to run 2 @ 400 so I tried that angle too but no luck so far,lol .