None really, less weight to lift, quicker shot. Probably not noticeable. I never use the square weight. If you have already assembled your carb with the weight just leave it in.
Actually I haven't reassembled. Working on bookshelves for my Grandson.
The package of weights etc. came with three different balls. One steel, one aluminum, and one what looks like plastic. I assume the lighter ones are supposed to give a quicker shot.
