Hi, the advantage of C18 over other compilers is that it is inherently compatible with other MC devices say their Zigbee Transceivers for instance.Although they can be programmed in HITECH and MIKRO but its really a pain.On the other hand C18 doesnt have that many built in functions like mikro C.The only "problem" with the compiler from microchip is that they dont have one for the 16F series which is ok cause most of the time people doing C use the 18F series(such as in the OP's case).