The answer depends on how familiar you are with C programming. Both CCS and MikroE have compilers for PIC24, they are rather convenient, coming with many built-in functions for control of peripherals. If you are already working with CCS C, changing to their 16-Bit compiler PCD respectively PCW is only a small step. Of course it's advisable to learn about the hardware specific details involved with PIC24.
The old Microchip PIC24 compiler C30 is based on GNU C, the new XC16 is Hitech-C, as already mentioned. Both are powerful, but a full application will usually involve a considerably number of include and library files for peripheral access etc. You can expect fewer compiler bugs with C30 or XC16 than with CCS or MikroE C. And you have access to the huge Microchip Application Library that can be seamlessly integrated with the projects.