never understood why you want the alarm chirp - if you can't hear the central locking banging away when it locks and unlocks you must be deaf!! (no offence intended to those that are or who are hard of hearing)
as for useful - live data logging with graphs is its most useful feature - ensures your motor is in tip top condition
useful for coding new clocks, coding new keys etc, enabling one touch opening with the key fob, auto-locking above 10mph