He posted good info without the 'h' in the username at icmag. Probably also at opengrow.
Will be making one myself sooner or later, I got a gavita hood (tripplestar, pretty neat allowing for different beam width settings basically but not good enough for 4x4, more for 3x4) and use a phillips magnetic ballast. I think I will got for the new 600/750 series, need to keep it small to keep a low profile (rental, electricity use...)
I wouldn't dare to really make a comparison with vertical growing, but one of the reasons gavita got so popular (in greenhouses, i.e. professional growers) is because their systems did a better job with phillips bulbs than phillips did itself, especially when it comes to penetration. It genuinely a classic, people being surprised with how low the hard buds go.
It's past bed time for me, I'll leave this thread open and post a few classic examples from 1-4 bulb "bread growers" tomorrow. One of the better examples I've seen here of similar grows is from
@AlphaPhase. Once you got buds side-to-side like that the only way to increase yield is grow 'deeper' colas. You mentioned 4-5 plants, which is actually quite common here for 1k watt because 5 plants is sort of decriminalized. Many growers have a tent or closet at multiple friends who just water the plants. It's how many coffeeshops here are supplied so they try to push the most out of 5 plants while still doing 5 or more cycles a year. They don't pull 1.5gpw though, that's rare, but 2lbs/1gpw is not uncommon especially with strains like the popular amnesia haze that is suitable to grow tall colas.
This thread sums up many of the basics, it's very rough, but a common starting point on this side of the pond where space is scarce:
http://rollitup.org/t/12-step-program-for-closet-virgins.860295/#post-11311162