All the advice I was given led me to choose the STX D40 Turbo Diesel Auto Dual Cab, which I picked up at the end of October 2009.
Having now done nearly 26,000km, I can say that I am extremely happy with it. I can take it offroad without fearing I'll get stuck. I can pull my current 1.8T van with relative ease.
Points against the diesel:
* More expensive service costs. Not a biggie in my book, because I'm paying less for fuel.
* More vehicle noise. The diesel is louder, especially when cold. I've gotten used to it already.
* It's not a race car. I had a Jaguar XJS, now THAT was a race car. 80km/h in a roundabout, 120km/h through a 35km/h corner ... yeah. The Jaguar emptied its 90L tank in 250km around town. 'Nuff said.
You know what I'd do? Go and drive both. See how they feel, hear how they sound. Listen to one go past. Remember that the diesel won't object to a water crossing (with snorkel fitted) but your petrol one will sit in the middle and drown.
You may never want to do a water crossing, but don't mind the sound of the diesel. Perhaps the sort-of sluggish feel before boost time is something you can live with - driving a small-capacity diesel IS different, and DOES take some getting used to. But you do that because of its capabilities, and its better economy (as far as I can tell).
Whichever way you go, good luck with it, and welcome to the forum!