I have the Space Grey X. I went to the Apple store to see if I should replace it with the Silver X. I played with the Silver one for 10-15 minutes and came away with the clear impression that Space Grey X is superior when you want to immerse yourself into the screen itself. The Silver X is great looking when you look at the back, probably better than the Space Grey X in that area but as soon as you flip to what is the purpose of the phone, the screen, the immersion is not as good as SG. The Silver has a shiny chrome on the edge which when viewing the screen in light shines and distracts you when you are looking at the screen, especially video and images. When you use the SG X, the Space Grey infused edge gives an immersion feeling as if you are looking into a window with black boundaries so the white, the colors and everything pops out even more especially in light conditions. your peripheral vision is not distracted even once by the silver shining in your eyes. When the screen turns on, your focus is thus on the screen edge to edge while on the silver, to me at least, my peripheral vision was constantly catching the silver glimmer on the outer edges of the phone.