I have no troubles with balance, what makes you think I have?
For efficient sailing you want your boat level on the waterline. Too much weight aft and the transom starts to drag, too much in the front and the bow starts to dig in to the waves. In both cases the waterline is shortened and the speed reduced (assuming the boat isn’t in a plane). But this is only the static weight distribution.
Think of your boat as two weights connected by a rod. It should be obvious that if you increase the length of the rod the dynamic behavior changes while the total weight stays the same. In other words, it changes the pitch characteristic of your boat. Having all weight as close as possible to the center of gravity makes the boat pitch more but it won’t dive in to a wave easy. With the weight all the way aft and front the boat is easier on the pitch but it will probably take more water over the foredeck and as a consequence it sails less efficient (slower).