We recommend large scenes like Warehouses, Farms, Stadiums. Where there is a large area for many cctv to cover. With EPOE there will be much lesser switches or optical fiber cable to be used, the installation is complicated and high in cost.
But the wiring needs to be reconstructed and the analog system needs to be updated to IP system, thus the cost of upgrading would my costly.
IF you are interested here are some cameras from dahua which are EPOE ready!