How do visual sensors compare to beam/vibration systems with PTZs?

The cost and efficacy of these solutions limit their usefulness, especially in small/remote sites. That is, installing two systems (sensor + video systems) is quite expensive when compared to a single visual sensor system (which has both detection and visual notification integrated into a single unit).
Further, the operational reliability of a visual sensor system is greater than multiple (sensor + video) systems which have more components, require complex integration, and view events from greater distances.