Much of a muchness, really; but, considering the age of the vehicles, it may be an opportunity to upgrade to the newer Subaru if the price is right.
But before you do, a Subaru owner on my staff tells me that the engines require more frequent oil changes; arguably a good policy, as this is the lifeblood of an engine, but also an added expense.
When the cam belt needs to be changed, the engine has to be removed from the vehicle, so this service can be expensive too.
You might also check the tyres. If it is fitted with Yokohama Geolanders, these were available only from Subaru at one time, but availability may have changed in more recent times.
If you are travelling the country, it will be easier to find a Nissan agent than a Subaru one.
Finally, both vehicles have been Towcar winners in Europe at one time or another.
– Godfrey Castle