We tend to have hot dry summers unless we have a hurricane. So I find my garden does better planted directly in the ground and I don't have to water as much. The fall/winter garden also seems more hardy. I use wide rows to give me plenty of room to work.
I really don't know the answer to this but I would suspect if 1 year was good a 2-3 year rotation would probably be the way to go to get maximum benefit.
If you have a shorter growing season bush beans give you a lot of beans in a shorter amount of time.
I have a fairly long growing season so I grow pole beans because I get a lot of beans for longer and I can stand to pick most of them. I have a bad back so I can't bend over long without pain...