CIC to NBT is nothing like the complete redesign that marked the move from CCC to CIC.
The basic interface and the way the menus work remains the same, but NBT has more modern and flashy graphics and is a bit quicker. Pro Navigation fitted cars have a touchpad on the controller, too.
If you have a choice of two cars and one is CIC and one is NBT it's worth picking the NBT one. If you need to spend quite a bit more then it's not worth it.