You can see the seam in the picture on the right if you look at the top of the sight between the front lens and the battery compartment/brightness adjustment dial. The link below will take you to the MRO section of Trijicon's online catalogue. The one thing that stands out for me is that there appears to be a seam running lengthwise on both the top and the bottom 'bells' of the sights on the original.
Holding the MRO up the picture, though, it's hard to see any difference. I haven't shot with the one I've got yet, so unfortunately I really can't tell you anything useful about it.
