I have used it over the years for IP cameras (and other devices - TiVo) for my own testing. I have needed to put a camera in a location that does not have a network connection, and I prefer to not need to run cable and drill in to my house when not needed.
I successfully used the original HD-PLC even with its lower bandwidth for a camera. I also have used it for temporary camera locations (or temporary PC, access point, etc). I used a 1.3 Megapixel H.264 camera, and had no problem streaming the video to an NVR.
The newer versions of PLC have much higher bandwidth. I would love one to have PoE out...
Once the devices are paired (they usually come as a starter pack already paired), all you do is plug the camera (or PoE Injector) in and you are good to go.
For a commercial installation, you need to be careful with the phases. Sometimes the master will not be able to reach the slave unit.
I have found it to be extremely simple to set up and very reliable.