Capacitive is often an attractive solution in the planning stage, sleeker, allows for software flexibility, but there is no tactile feedback, and the response is instant, so there is zero room for error. While hardware keys can be more expensive and complicated, and force harder decisions earlier in the process about the specifics of the interaction model, I think they are nicer because you can feel them. Better user experience. Think of how fondly people recall their iPod wheels. We had a bit of a golden moment there in hardware/software interaction and we rushed past it to get to the all encompassing rectangular display… but that is the thing about pendulums, they always swing back…