Well here's what a better binding will do for you, and it has nothing to do with your DIN setting!
Bindings serve a few functions:
First they form the connection between your boots and skis. This should not be taken for granted as the more solid that connection the better control you will have over your edges, especially on firmer snow. If your boots soles are worn from walking this connection is compromised. If your binding system has slop in it when the boot is clicked into it, your connection is compromised. Ever notice how racers and expert skiers are diligent about wearing cat tracks or some protective measures to keep their boot sole from wearing?
Secondly, your bindings offer retention. This means the keep you in through oscilations caused by external forces such as chatter (high frequency) and bumps or internal torques (low frequency). Some bindings offer better retention and shock absorption than others, generally higher end bindings offer better retention. It is the faster hits or high frequency, external forces where retention becomes important. Another point in this area is how wide the binding platform is and how much leverage the toe wings and heel cup offer. Some are narrower offering less leverage over the ski edges and some are wider, generally higher performance bindings, offering stronger leverage to edge the skis.
Thirdly, your bindings are designed to offer release when the time arrives. In general this is what the whole DIN standard chart is about. All bindings should release under a slow or low frequency twist and pull, in the same DIN specified range. So a 5 on a low end or high end binding or a Salomon or a Look should all be the same. These release values were derived from breaking cadaver leg bones to determine safe setting based on weight, height, age, boot sole length and aggressiveness. If there is one area where bindings are created equal it is this area.
Fourth, every binding creates what bootfitters call a "Delta" angle which is the angle created between the boot sole and the ski top sheet caused by the stand height difference in the toe AFD thickness compared to the heel rest thickness. This angle is one of the four parameters on the sagittal plane that affect your fore/aft balance. Once you have found the optimum stand height differential for your stance it is wise to replicate this angle on all your skis.
So in summary when choosing a binding, I want the strongest most solid connection to the ski with little to zero slop, one that offers the best retention in chatter and high frequency hits from external forces, and offers the smoothest release when that time comes.
Hope this helps your understanding of a bindings role in your skiing!