You know its kind of funny...everyone assumes that my climate is just the greatest, but really its not(I have heard local growers say that you cant grow worthy pot up here, and juding by many of the plants I have found its almost true!...ahaahahaha). I have come across hundreds, even thousands of plants over the years that would yield 1-4 oz, but never once seen a 1lb+ plant grown without care(
@Darth Vapour is one of the very few that I have ever seen grow a 1lb+ guerilla style plant close to my area). You get out of the plants what you put in.

Give them free reign for roots to spread, and proper nutrients and boom! 2lb+ every time.