They look different to me in the bottles; the China Glaze is yellower, the Orly more blue. But on the nail? Well, look:
They're really, really close on the nail in just about every lighting condition. I didn't manage to get any pictures where I could see any significant difference between them. In bright sunlight, I can sorta kinda tell them apart, but my camera was not impressed and refused to take any decent shots when I took these greens outside. If I can keep only one, and the fullness of my Helmers is telling me that day is coming, I will keep the Orly, mostly because I like the bottle better—it holds more and it's got that easy grip handle—but also because of that slight blue tinge to it; I think cooler tones look better on me.