Hi mare, I was in the same boat about six months ago, with a plan to keep the vehicle for 200,000 km or 4-5 years. I was set on the 200 and thought I had done my research. Had strong views on the petrol diesel debate, and have spent many nights around a campfire espousing the torque and fuel efficiency advantages of oil burners.
Ended up driving the Y62 really just to rule it out. Came home in shock, because IMO the vehicle fit out and finish was miles ahead, and the 7 speed auto and 5.6l v8 was brilliant. The factory diff lock was a bonus, Slept on it, recalibrated my thinking, Bought one and haven't looked back. Oh and the 30k saving was nice too.
I get your thoughts on Diesel engines, I suggest if you are about to drop $100,000 on a car, just drive the Nissan to rule it out you might be surprised. I was, and many others were too.
I know the thinking is a bit different to many others on here, and I love the cruisers too.