Do you have the white? How would you compare the difference between the backs? The black has a very soft-touch matte finish, and I have heard the white is more solid.
I do have the white one. From what I understand the white is more of a harder plastic than the black. The black feels a bit more rubbery. The back on the white one still feel great in hand. One of the best feeling phones I have ever had. Just a bit different. Also the white one has kind of glossy side, and the black takes the back and puts the same material on the sides.
White has the cheap & nasty Samsung style plastic at the back, not to mention the homemade, half-and-half look. No thanks Jeff, black all the way.