i use a 2012 xtrail 171hp for my ribcraft 6.8 and have no problems, great car.
however, i would say you don't want to be towing anything larger than this IMO. I actually got mine re-mapped (not the cheap ebay chip crap) as it was struggling i felt, even though the specs say it can handle a lot more it has to be said, it did need more torque IMO when i got the bigger boat. when i had my old avon 560 it was superb, bags of power. with the re-map i now have considerably more torque and it has transformed the car, i wouldn't bother though for anything less than 1600kg.
the above advice i would be careful with, if you do get a newer xtrail then i leave it in auto mode.
can't leave it in 4wd mode either with mine, as soon as you go above 20-30mph the 4wd disengages unless the computer deems it needs it, not sure if andyjcox has a diff year/model to me though but i've never heard of one staying in 4wd all the time?
auto mode/2wd mode doesn't make an ounce of diff to fuel consumption on mine.
whilst towing i get about 32-34 mpg, on a long run it will get up near 50mpg, can't ask for more really. i should add the remap got me circa 5-10% better fuel economy over standard.
i really doubt there are many better soft 4wd cars out there.
i can say it blows a soft 4wd kuga away, that barely moves the ribcraft as my old man has one.