IMO, pretty much useless. I had my car already for 9 months and I can only remember once where the HBC actually switched ON.
Sometimes I activate the system while driving at night on dark roads hoping for it to work, but in the real world and real situations I have very good lightning from the roads, and at least in my experience for the system to operate properly, I need to be driving in real darkness and with no upcoming traffic which pretty much never happens.
Perhaps this feature is more useful for those who live outside the city or when you are driving very often on dark roads where lightning conditions are bad, but I mean wouldn't be easier just to put the headlights on high beams already?!
Members on this forum have discussed additional automatic car features such as "Rain Wiper Sensor" and "Automatic Headlight ON", and some prefer to have full control over the features of their car, which IMO applies to the case here.