Alarm ringing is pretty much the same thing. When you swipe the green bar (just a little), the alarm stops and you get the actual alarm dialog with "stop" and "snooze" buttons. I believe if you don't press anything it's similar to "snooze", but I'm not exactly sure (whether it will always ring again). Of course there is also the "flip to shut up" thing as usual.

The N9 is by far the most convenient alarm clock I have ever used, phone or not. I also love the tone, as I usually have trouble finding a tone that is not too jarring but which I don't just sleep over.

I rather disliked the default settings of the N900 in this regard, as the sudden vibration always woke me up with a shock, while turning off the vibration made it too easy for me to oversleep. It was also much more cumbersome to configure all around.

And this is pretty much the theme of the N9 to me: More convenient in every day life.