When you have to do with real people renders you can't have an anime background now, can you?
Sure you can add abstract bg and such but it aint my type so i use city/building stocks instead.
As about the specific bg, yea i used it in a couple of signatures (1 2 3) because it blends in most of them perfectly.
As about the C4Ds used, no they are not the same.
You know when you create a C4D u stick to the prototype style you invented and you change the angle, shape of it.
What i wanna say is i use C4Ds from a certain person whose C4D style varies the shapes and angles but its style is stable.
Oh, and one more thing the reason i keep using the same resources lately is,
1) because of the limited access i have on them and
2) because people love them the way they are.