Nice, I'm glad people are using my G4 Image editing I did a couple days ago!
I am on Verizon and know I want to end up with the brown leather back, but was disheartened that Best Buy or Verizon Wireless is not selling the brown leather as an option at this point of time. So did that photo editing to get an idea if I would like the metallic gray with the different backs or not. On T-mobiles site, the G4 with brown leather comes with gold buttons / camera housing. Which does blend in perfectly with the brown leather.
Also, one HUGE thing to note is that the front of the phone only comes in one color. No matter what color of back or leather option you get, the front of the phone will always have that black diamond pattern. I was originally going to order a white G4 and and try out the brown leather down the road. But after I noticed that, figured there was not much of a point.