I set my radio alarm, but only as a safeguard as I have never actually needed it. My mental alarm is flawless. Whether I have to wake up at 10:00 for classes for 5:30 to work with my dad, I wake up a few minutes before my alarm goes off without fail. But I think the physical alarm may be setting my mental alarm; making me wake up a few minutes before it goes off because I HATE the sound of an alarm in any form!