I don't have specific information for that new setup.  However, I've had
four Nissan 4wd vehicles since 1990, include two QX4s since 1999.  The
only problem I had was when some moron (not me) put the wrong fluid in
the limited slip differential of my first PF.  The other three also had
LSDs, but no problems with them.  So, my opinion is that Nissan is
knowledgeable and competent about designing and building effective and
reliable 4wd and AWD systems.

The system has been on and under 1 of the most revered vehicles in the life
of NISSAN.
The Prince AKA Skyline and GTR AKA Infiniti G35.
It is well over 20 years old and has been on more race tracks and mountain
races than most
any other vehicle AND WON more titles.
A testament is that the Skyline GTR holds more 1/4 mile and 1/8th mile
records in the AWD/4x
class than any other MAKE.
Now if they can put down over 500HP to all wheels time after time and trust
the Atessa AWD,
I feel you would be hard pressed to do better.. EVEN in the Subaru.
In Asia the 4wd sedan monsters go:

Skylne GTR
Mitsubishi EVO
Subaru STI
The Subi and the Mitsu fight out for 2nd place while the Nissan sits back to
see the challenger.

Just a Little Info

Infiniti is the #2 most reliable brand behind Lexus according to JD
Power.  You have a 75k warranty on the drivetrain, 60k bumper to bumper.  
I wouldn't worry about it - with peoper care & feeding, it should last a
long time.  

As for me, I picked up a G35s, 6MT a couple weeks ago and LOVE the car!

Just saw an episode of "Carography" on cable t.v.

Chevrolet ran a Rochester fuel injected '57 283 c.i., 4 speed Hurst,
pre-production sedan up Pike's Peak and broke all the records for elapsed
time to the top.  I saw the amazing documentary film with my own eyes and
am 100% convinced that the less-than-$3,000 car could outrun a $40,000 Audi
any day of the week.