The ability of using PLCs in real time, so we can see what's going wrong during production process even if it happens far away from our control room! It needs some training for first users because there are many features but easy enough once you know them well (it does not have all functions).
There isn't such functionality as "I want this function" button like other systems available online; instead I need programming skills which takes lots of my precious times since i'm working remotely most of time from India while running an international business operation here in Indonesia at same place where manufacturing site also located nearby.