I've used the N950 quite extensively both totally drunk and hangover. I'd expect the same findings apply to N9.

My previous phone was N95, so this is compared to that.

The keys are much easier to hit on N95, but in practice I found it required quite a bit of concentration as you had to remember how many times to tap a key to get a specific letter. The result was that it required constantly quite much concentration, which I found surprisingly difficult a task when sufficiently inebriated.

The N950 on the other hand has quite troublesome small keys in VKBD which makes writing quite a frustrating experience when your IQ has fallen couple of deviations due to alcohol consumption. Auto-correction helps somewhat, but can also result in hilariously mangled messages that you're ashamed of when waking up from the stupor.

Since receiving the update to N950, which includes the Swype keyboard, I've come to think that Swype is the best drunken keyboard. You just slide your finger along the keyboard in approximately the correct paths, let swype do the hard thinking, and after you've composed the message you have to just concentrate once proof-reading and correcting the few words that swype guessed wrong.

I hope that helps someone.