I am sure the new and larger QX50 is going to be an awesome vehicle. Obviously overdue (but also a nod to the EX35's ahead-of-its-time design) it updates its design, its engine, tranny...everything. Although not at the top of the 2.0 turbo performance world (see GLA45 and CLA45 AMG and Honda Civic Type R), it is a very technically advanced and modern engine delivering plenty of HP and torque... paired with a heavy body (3810 lbs fwd to 3957 lbs AWD) and boring CVT transmission. I think the transmission being a CVT limits a bit of the fun factor.
Then you have the obviously smaller and sexier QX30S (sport FWD)... It has the Mercedes 2.0t with decent HP and torque, and awesome and fun as heck dual clutch tranny with 7 speeds and paddle shifters. Although its 2.0t is not as powerful and the Infiniti 2.0t, the QX30 is much lighter (3280 lbs FWD and 3475 lbs AWD)..
0-60 times for each actually favors the QX30S, but are very close (QX30 6.2 FWD/6.4 awd to QX50 6.3(awd) 6.7 FWD)
Now to the Dinan point of my post !
If you don't know DINAN, they are a tuning company that specializes in German Turbo engines... well they have a cool little turbo boost controller ($295 usd) for the Mercedes 2.0t...a simple plug & play device that adds up to 30 HP and 40 lbs/torque and gets this engine up to another level (from what I have read from actual users).. up to 238 HP and 298 lbs /torque!
Add that to your QX30 sport and its 7 speed DCT and that spells FUN. I will soon let you know the first-hand, fun-factor!