The biggest dif is in the radio. 2.4 gHz Spektrum with the CX2 vs 72 mhz FM for the CX. This makes the CX2 a better buy especially if you live in a big city or anywhere radio interference might be a problem. Body styles are a bit different between the two other then the radios. Converting a CX to a CX2 would not be worth the trouble or money as the dif in price is negligible compared to the cost of switching the radio Tx/Rx to the CX.