I looked at the one link to the guy with the 250W horizontal scrog. What I noticed was this: The plants were way too crowded and there is simply no way 250g can physically occupy that little space. The poster claimed 40 tops in total. At 6.25g per top 40 X 6.25g = 250g. So, every bud in his setup would need to weigh 6.25g. That is a bud the size of a large banana. I don't see any monster buds in that thread and 40 of them physically would not fit into that space. And this is only 1g/W.
The largest hole in the vertical grow theory is that these plants are not designed to be lit from the side. The plants form a cone for a reason. Think about a cone for a moment. If you light a cone from the top the whole plant gets light (presuming the bottom branches form the canopy). If you light a cone from the side, the whole other half of the plant is shaded.
I must admit, the thought of completely surrounding the bulb is interesting but I can't help think that all this does is redistributes the light over more area instead of focusing it on less area. Think about what happens when you adjust the focus of a flashlight, the light is more intense when focused and less intense when spread. Removing the reflector should have the same effect. A good reflector reflects over 90% back down onto the plants so we could think of this as the plants getting 190%. A vertical grow simply spreads the light out to get 100% X 2 - granted there is a small loss due to the reflector. I fail to see how this is different than a light mover. Also, using more, smaller lights spreads the light evenly which is hugely beneficial. I can see how those with a 1000W light would benefit from raising the plants on the edges to keep them equidistant from the light. More lights or a light mover alleviates this problem.
I've seen a lot of guys on the internet trying to get others to look up to them as some kind of guru and I have seen many succeed. I'm just not the kind of guy who buys into that sort of thing. If I see dozens of guys doing vert grows and showing massive yields I might try it, but until then I remain skeptic. Besides, in those systems all it takes is one failed pump and you have nothing. I prefer failsafe systems like a DWC. maybe I would try a Rockwool drip vert setup, but not a NFT type that will die in a day if your pump takes a shit.