hmmmm i think both prawn and weitfras are closer in their thinking than this argument shows.
i think it all comes down your style of growing and the power budget you are prepared to allocate for the returns you get on your crop. if we boil it down to the basics the general idea is to get the largest amount of mass/flower within the least amount of space and use the least amount of power possible.
take two polar opposite examples, number one the unlimited option - you have unlimited space and unlimited power budget ie fields and fields of fertile soil and the sun. the sun acts like a really big cob running at approx 380 yotta watts or 380,000,000,000,000,000,000,000,000 watts (dont worry your not paying the bill!), luckily the sun is hung far enough away that you dont get a hot spot and all your fields are bathed in an unmeasurably even light (forget about clouds ect for this). you can have fields of 2 ft tall plants and fields of 10ft tall plants, it doesnt matter they all get the same intensity (inverse square law to small to measure), LAI doesnt matter, power consuption doesnt matter (its free), this method is always the most productive but not the most efficiant, after all the sun is also lighting the rest of our solar system (wall losses, but again we are not paying the bill so fuk it).
example number two, the very limited option (ie how we all do it) - you now have very limited space and a limited power budget ie under stairs cupboard, grow tent or spare room and artifical lighting with a power budget that costs £$£$ (you are paying the bill now). so now every square foot counts and every watt counts, so a single light point doesnt make sense anymore its just not the most efficiant way of evenly lighting your canopy. even if you had the height in your space you have to hang the light too high(and ran harder) to get an even spread on the canopy resulting in wall losses and wasted watts. in this secanario plant height definitely matters, LAI definitely matters, wall loses definitely mater ect...its all about getting your flower to grow in the goldilocks zone of that even photon saturation.
i think like this - start with grow area, say a 4 x 4 tent then allocate a power budget lets say 37.5 watt/sq ft so that gives us an overal budget of 600watts. the best use of that 600watts is to get as much of it as possible converted into photons and then get them photons spread as evenly as possible over that goldilocks zone.
so with led leading in the efficancy/photon genaration per watt catergory we pick them, so say a samsung lm301b. now we can work out how many we need, for the budget concious grower he will want to spend less on the lights(ie fewer diodes/boards/strips) and run them hard.
at max curent a 301b is 200ma at around 2.95 volts so watts= .2 x 2.95 = 0.59 watts, so with our 600watt budget we need around 1000 diodes, you then have to shop around and see what boards/strips are on the market that fits your budget/diode count. this normally is roughly 4 288 "quantum" boards or 10 strips with around a 100 diodes each. then you have to spread the boards/strips over the canopy to get the most even coverage at your desired intensity for as least waste as possible, for this above scenario strips will always win, lower hanging height, less loss better spread.
now for someone where budget isnt a concern (talking light cost not watts used) they can go for more diodes and run them softer. (and we will take this to the extreme budget£$/and diode count) so we take the 301b again and run it at 65ma at around 2.76 volts, = 0.18 watts so now we want around 3300 diodes. of we go shopping and now we can get around 11 "quantum" boards or 33 strips for our budget. in this scenario and at the extreme i think boards probs give a more even spread of light. at this diode intensitity(number of, not brightness) the average strip build has too many diodes too closely grouped all in vertical lines, i think the boards win here...
but... if you take a double row or even tripple row strip with the diodes spaced a bit farther apart vertically, well i think the strips probs edge back out the boards???.
so to recap the sun is free and the best lol.
and id say say strip builds beat board builds for the average grower 80% of the time untill you get crazy then its probs a draw....but strips for the win