The CRTs have three Modes GPC, SM and PL - every program has different displays for each mode. The two Main modes in SSM2007 are GPC, used for on orbit manuvering and system settings and SM used for Mission Payload OPS.
All four CRTs allow the crew the same functions. the three forward CRTs are controlled from the C2 Panel while the Rear CRT is controlled from the R11 Panel.
Because OPS1 is used during the launch phase - it is mostly used from the Forward CRTs.