Onboard USARTs are well worth making use of. I write some fairly complex programs for commercial MIDI use and often have to use the available USARTS because the PIC software processing can not afford enough time to concentrate on the serial data directly. Dealing with serial communication just in software is ok but the great advantage of a USART is that it looks after itself by operating at the same time as the PIC is processing software. I find them particularly useful for receiving. You can use the appropriate interupt flag (which can just be polled rather than interrupt if you like) to 'tell' the software when a new byte has been received. For transmisison, a similar flag lets you know when the buffer can accept a byte for sending out. The only thing to watch is making sure you get the registers associated with the USART set up correctly!

John R