My friend who I got my cheese from has a warehouse grow and he uses the ebb n' gro system. I'm by no means anywhere close to an expert but I'll still give ya my thoughts as I am also one of those forward thinking people and have given this question some thought already.
For one, the question can only be answered in very general terms. There's so many little specifics that are unique to each location, especially in a large commercial setup, that it would be pointless to give specific details and say "this is how you do it" unless you are building everything from the ground up.
Hydro is definitely more efficient both in speed and production. If it's a medical grow where numbers count I would go with an ebb n' gro. Ebb n' gro's are great systems that allow the buckets to be directly on the ground so you can grow them big. They are a little quirky...sometime the pump doesn't shut off and floods your room. Sentinel also makes one that's digital, has a water sensor and alarm, and better buckets. Personally I'm a little partial to scrog right now so I would do that on a large scale. If you're a guerrilla grower you may consider a large aeroponics array and grow shorter plants in a sea of green. I think one of the keys for efficiency is to do a setup with the fewest amount of reservoirs as possible. DWC won't be the best method I think and normal ebb n' flow is a nasty green mess.
For environmental controls, pretty much everything is just bigger. You use co2 burners instead of tanks and you may have several small rooms or a couple big rooms, sealed environment or vented, cold climate or hot......all of which completely change your setup. two cents please