George,
IMO the tree form for containers seems to be not only easier to maintain, but also relatively productive. I started a Topic detailing the simple procedure to achieve a good shape within a reasonable amount of time and I've also linked it to other more experienced growers that recommend the tree form. I have a 3 year old Celeste, that was purchased last year, it was nursery trained in the bush form. It has been a little difficult to handle, repot and root prune. If it was not for the fact that it was my single most expensive fig plant purchase, I would get rid of it.
BTW It is also the least productive fig plant (plant in general) that I own. I have yet to taste one fig from this bush (it dropped all its figs last year)