Just returned from the local unveiling of Trooper at a pub here in Tucson. It was an incredible night. All Maiden tunes all night long, karaoke, of which I sang "Fear of the Dark", and, of course, numerous pints of Trooper!
I have now consumed Trooper in three different ways:
1) As Nicko suggests, warm. From the bottle. I liked it. It was decent, a very clean finish with minimal aftertaste. However, the repeat drinkability was pretty low.
2) Cold, from the bottle. Fantastic. Smooth, but still dry and bitter. Zero aftertaste, good flavor.
3) Cold, from the tap. Four times. It's really good.
I thoroughly enjoy this beer. I am a fan of bitter ales, and this one is quite solid. It's not the best beer I've ever had, and it's way too expensive, but I could drink this all night (if only someone would bankroll me).