On future battlefields, increasingly more sensor information will become available for military commanders to support mission execution. To improve (shared) situational awareness, decision-making and communication in face of this increased amount of information, the design of command and control (C2) systems must match the mental models and information needs of commanders. We compare two C2 interface variants, based on different rationales: decision support and personalization. Decision support integrates large amounts of information into categorized overviews, while personalization provides flexibility in (sensor) data representation and comparison. Four experienced commanders carried out simulated military field operations with both interface variants. User actions, eye movements, decision-making quality, situational awareness and mental effort were assessed, as well as interface usability. From this, we identified which interface features provided added value, depending on the tactical situation. This way, the best of both worlds can be combined to improve the design of future C2 systems. Copyright is held by the authors.