I have seen somewhere that with an application form you could turn the Greek lisence to a CAA one, but having a hard time to believe that.
Was also adviced by a key person within the school to stay away from the GS.
I believe the flying is quite good due to the fact that they are using diesel ac which is cheaper than conventional fuel.
If you are planning to do the long distance why not do the Bristol and then go there for the CPL and the rest.
But be worned,even if you untertake the GS in the UK and the CPL in Greece, you still get a greek lisence.