DIN is the Duetsche Industrienorm, an international standards organization that the ski industry has adopted as their international standards organization. according to the DIN, DIN settings, are DIN settings, period! a 10, is a 10, is a 10. it means that an individual skier code ( which is based on a height/weight formula intended to generally determine the average size and therefore strength of bone for the skier, the skiers age ( which can influence bone density), and the style that they use moving down the mountain), then taking that base skier code and using the length of the boot sole ( which influences the leverage on the bones of the lower leg in twist and forward lean), to determine the actual setting for the binding that would best suit the skiers needs to protect the bones of their lower leg in twist or forward lean.
long winded explanation, however the point is that we now have the basis for what setting the binding will release the skier at a point below the line of potential damage to the lower leg. or for lack of a better term the DIN setting. this setting is one dimensional. this is what this thread has been debating without direction for way too many posts. it also has little to do with what binding the op that started this thread should get.
so the down and dirty answer for the op is that you can ski on any binding that has a number on it that matches your desired setting, but only for the single dimension of lower leg protection. if you are at all concerned about protection of all your stuff above the lower leg, you should read on.
the better response for the op is understanding the part of binding function that does not have a number that is presented by the binding manufacturer, the DIN, the pimply faced retard that is showing you the binding in a ski shop, or so far any of the participants on this thread.
the issue that needs to be understood is the bindings ability to absorb the shock and ground forces that are developed from the speed and style of the skier while moving down the hill. this is where the DIN norm gets a little fuzzy. in addition there is really only one way to figure this part of the formula out. the op needs to by the cheaper ( lower DIN ) binding, set it on the number of his choice or the number recommended by the chart, then go out and ski on it. if the binding holds this skier in during all of his/her normal skiing patterns, and is able to release before serious injury occurs to the lower leg, we have a love match. no need to look any further into the correct answer to the op's question.
however, if the skier finds that set on the recommended setting the binding and boot tend to part ways at inconvenient times, you would need to consider some other alternatives. you could buy the next binding size up, so that you get more shock absorption. because of all the erroneous analogies talked about on this thread, you are probably wondering where that additional shock absorption is going to come from if you get a binding with a higher DIN. ok now we are getting somewhere, the answer is bigger more powerful spring and more mass. more mass has the ability to absorb more energy. absorption of more energy means that the binding will be able to deal with multiple impacts and bigger impacts of force that are coming through the boot/binding interface from speed and ground force.
so what does the bigger binding, more expensive binding net you? it gives you the ability to keep the binding at a DIN setting that is relative to protecting the bones of your lower leg, while giving you a greater margin for speed and recovery to protect every part of your body above your lower leg, that would be at risk if the boot and binding part company at any given time that is not anticipated. you are paying for greater mass and greater elasticity.
binding selection is not a perfect science, it at all times is a compromise between the bindings ability to let you out in time to prevent serious injury to your lower leg below the knee, and at the same time have the ability to absorb the shocks to keep the boot from releasing from the binding so you can continue down the mountain.
so, a 10 is a 10, is a 10, is a 10. and if the binding has your number on it, you can ski that binding. the issue for for the op is whether the binding with his matching DIN number has the ability to overcome the amount of shock that he will be presenting to the binding through the boot sole. if it is not you can either upgrade the binding to one that still has his number match, but has a greater ability to absorb shock, or you could attempt to increase the amount of DIN which by doing so will compromise the bindings ability to release at a safe point relative to the strength of the lower leg bones.
based on the op's stated style is 3+, i strongly recommend that the op spend a little more money to get a binding that can absorb shock at a higher level for a higher price.