It is, in fact, the user interface from hell.
For the life of me, I can't figure out how to disable the alarm from going off. If you plug in the alarm, set it to alarm at 8am, as far as I can tell, for the rest of its life, it will do so.
And every time it does this (go off, when I don't want it to) I spend 20 minutes pressing different combinations of buttons. I think, if I hold down 'cancel' and 'sleep' at the same time, it'll work. It never does. I always give up and pull the plug.
It turns out, innovative user experiences aren't always a good thing. If this clock used the same approach every other clock radio had used, it would be just fine.
What on Earth were the designers of this clock thinking? And did they ever test it out first?
Moral of the story: even the simplest user experience can be broken if you aren't careful.
Update: Specifics about this device:
Brand: GE Model: 7-4837B Frustration Level: Very High
Thanks Nick for suggesting I provide this info.