This doesn't seem feasible for people that either (a) have naturally longer sleep cycles and are thus prone to getting to bed later and then sleeping in (if not

This doesn't seem feasible for people that either (a) have naturally longer sleep cycles and are thus prone to getting to bed later and then sleeping in (if not controlled, it adds up), or (b) have to be or do something by some time in the morning. I'm both and I can't rely on my natural sleeping patterns to wake me up and get the kids to school/care. That said, replacing a adrenaline-pumping/panic-inducing alarm clock with something that gradually increases sound or light sounds like best of both worlds. You can still rely on getting woken up when needed, and there's no need to shock yourself to it.