I had an '07 Navara for a while and loved it except for the high ratio of the 1st gear (manual) when pulling away from a start anywhere. Not sure what the new ones are like though, this would be a problem towing any weight and trying to hill start, I would think clutches would suffer. An auto would be the choice in this instance, saying that the Nav was great, heaps of power and comfortable to drive. Do the new ones rear seats still fold up? Even with the '07 the difference between the Thai and Spanish built, one did and the other didn't (just going from memory, 6 years ago at 50 is a long time
).
Now the Triton, I have been driving 1 for the past 6 months, 3 days a week for about 5 hours a day. In my opinion they have the worst front seats and driving position, my back was killing me after a couple of hours. I'm 5'8" and average build so it's not a size thing.
Mick