I know lst will increase yield in a small area, but what if you have a big space and a wide area would you still want to do lst or let them grow naturally?
It seems like larger areas work for larger plants, sog, or ScrOG. It's really all personal preference. You can get away not LST'ing for HID lighting, but I think LST is absolutely necessary with CFL or floros.
I have found that some sort of Low Stress Training is always beneficial. Anytime I have just let them be my yield was just a bit smaller.