Intel HEX file is a more secure way to store your binary executable file on your disk or floppy. When having large gaps in your code, it is also more tight than binary executable file.
Every line in HEX file has its own checksum byte at the end of line, so the error checking is double:
- line checksum
- disk CRC checking
HEX file is also more sutable to send over a serial line for it has only ASCII characters included.
You can develop your own transfer protocol to send binary file to the serial port, but then you should add some error checking routines to find out if there was an error during the transmission of the data.