Nothing. The main advantage of those pads is that they are very thin, lightweight and completely moldable. On top of being self-adhesive – and requiring no bandaging – you can also cut them into tiny pieces to suit any kind of wound at any angle. A single pad the size of an standard weave pad can be cut several times to cover several wounds. You can fold them and fit them almost anywhere. You don’t need to sacrifice anything to add them to your kit unless your kit is so full of stuff it’s ready to burst, but if I were forced to replace something, just for the shake of the argument, I would remove a few band-aids because you can cut the pad to perform the exact same function of a band-aid if necessary. I speak from personal experience. My grandmother suffers from constant venous ulcers in her legs due to clotting problems and these little things are a lifesaver. Before, we used to spend a lot of bandages, tape and pads just for a single wound and those would need daily replacement. Furthermore, the bandaging only exacerbated the poor blood flow problem, but one of those hydro-colloid pads can be cut to be used 4-5 times before you have to get a new one.