Capt Billy, there probably isn't any disadvantage as far as strength is concerned, I think Ithaca used it on these guns because of cost. It was less expensive to cast the frame rather than forge it, as it was made to sell at a low price. I have never seen one with a broken frame but I believe that frame failure is a combination of bad design and improper loads. If you inspect a Flues action you will note that there is very little metal left in the bar under the standing breech because of the cocking arrangement. Combine that with loads the guns were not designed to be used with, you have a disaster waiting to happen. Western Arms and 311 Stevens were made to sell at about the same price, they are both dependable functional guns made for utility not beauty.
Jim A.