Paesonally, I've pulled 6 lbs off 1 plant, and got 5 off many. I've seen 10 lb plants. I'm not shooting for big plants this year, I just want to get a few done. Tall don't mean shit when it comes to yield ya know......10 ft tall or 5 ft tall, doesn't really matter, it's the girth and weight of the buds, and the bud site count, not height. I had a 16 ft tall plant couple years ago that didn't pull a lb. I've had 3 pounders that weren't 4 ft tall.
I think most people go for as big as they can get most of the time, but growing monsters takes alot of money, work, time and space.Everyone don't have that leisure. I'm stoned and rambling.........I'll shut up now