The most noticeable difference between the Attitude CS and the Attitude CTS is the functionality. With the CTS being a touch screen interface and the CS using old school buttons. Naturally, the CTS has a much larger screen than the CS. With the CTS measuring at a gargantuous 4.3 inches the CS comes in at a measly 2.4. The added screen space also makes the CTS more ideal for the optional back up camera, which is not an option for the CS. Those are the basic differences in the Attitude CS and Attitude CTS, to find out more buy both of them.