Personally I have bought the RR NIB. It was my first NIB ever, but that was because the ECLE was not available anymore. It was very nice, but the green one is THE one. As ladyslingshot mentioned the wooden apron is the differentiating factor. It makes the ECLE unique amongst all pinball machines. Also the cabinet art is much deeper in color and more shiny than the RR. I had them next to eachother for a few weeks so the difference was clearly visible.
I sold the RR and now own the ECLE with the castle walls, tornado and toto from the RR and for me it is the version to have.
By the way: I also had a standard version (also a few months next to the green one) and I noticed that the monitor of the standard was better. Deeper blacks and sharper image. I tried a lot with the controls but could not get it as good as the monitor in the standard. It were completely different monitors also. The one in the ECLE had its own case and power plug and PSU , the one in the standard was decased and got its power from the PSU in the cabinet. They could not be exchanged with eachother.