Mine is quiet. It is funny because inside it nice and quiet and with the music on a "normal" level but step outside with doors and windows shut the music is loud...sounds like I have it cranked inside.
+1 on not removing panels to add sound proofing. Unless you have bad rattles it isn't worth the risk, to me. The WK2 seems to be better sealed, around the doors and windows, than other vehicles.
My Overland is very quiet. My previous vehicle was a Buick Enclave, which was even quieter, but that was a completely different kind of vehicle. For the capabilities that come with the Jeep I expected a little more road noise, but was pleasantly surprised how quiet it is, even at highway speeds, and on rougher road surfaces.
Hers: 2008 Jeep Compass Sport
Mine: 2014 Jeep Grand Cherokee Overland V/6 ORA II
Michelin LTX M/S 2's
My GC is extremely quiet and I have the Good Year Silent Armor tires that come on the Trailhawk, which (contrary to name) are louder than the All-Season tires on most other models [I test drove an Overland for comparison].
Now my JK is a whole different story - 35" BFG KM2s and thin doors and top make for one of the loudest cabins of any modern vehicle; still doesn't bother me. The hum of mud tires is like music to my ears.
One thing that I thought was interesting was that if I want an even more quieter ride then I must close the sun shade as well. I thought closing the panoramic sunroof will do the job but I must close the sun shade as well. Even though sun shade is a cloth type material but I guess it still seals the gaps and helps in reducing the noise levels.
2012 JGC Overland - Max Steel
I don't know why anyone would want to add sound deadening insulation to a Jeep Grand Cherokee but to each his own. My GC is by far the quietest vehicle I have ever owned and quieter than my boss's S65.