@Tetnobic the hw* functions is a way to abstract the underlying hardware. Many MySensors fans use non-avr hardware, for example ESP8266. You can of course choose to optimize for a single platform in your own sketches, but we strive to make the MySensors example sketches available for as many platforms as possible.

@Tetnobic sleep duration is in milliseconds, thus X * 60 * 1000 for your case