Alarm - Sometimes it goes off, sometimes it doesn't. Sometimes it goes off 4 minutes after it's supposed to, sometimes it goes off 10 minutes after it's supposed to, sometimes it goes off on time. It's usually at least 1 minute late. I don't know whether this is a software problem or a hardware problem.
Nokia 920: I have multiple alarms set, used on a daily basis. The only time they haven't activated precisely as set, is when the battery has run dead - which, unfortunately, happens too often.