I've always had V8's in my Grand Cherokees. I took a gamble and leased a 2014 Overland with the gas V6. Any reservations I had about buying the gas V6 disappeared on the first drive home with it.
I've only got 1300 miles on it so far but I can say that I haven't been disappointed at all with it. I have a 25 mile one way commute to work that consists of a pretty even mix of highway (60 mph), freeway (75 mph) and stop and go city driving. I'm averaging 21 mpg combined with it (EPA estimates 19mpg combined) and I don't consider that bad at all for the few miles I have on it as well as not driving it in Eco Mode. I haven't owned a vehicle since the 1980's that got anywhere near the EPA figures much less exceeded them.
The gas V6 has a surprising amount of power with good acceleration. I live in the Mississippi River valley and we have some pretty good sized hills around here. On one of the largest, I had no problem maintaining the speed set on cruise control... the transmission only dropped down into 6th gear. I couldn't detect any strain on the engine to maintain speed during the climb up. LOL... quite a different story from my 2002 with a 4.7L V8.
I can say this about my 2014 so far...
Hands down, it's by far the quietest vehicle I've ever owned.
It's the smoothest shifting vehicle I've ever owned.
The ride quality is impressive and is something you'd normally equate to an expensive, full size luxury car... not an SUV on 20 inch wheels. It makes my 2008 Honda Accord feel like a Campbell's soup can on wheels.
The U-Connect system with Nav is one of the most intuitively easy to operate systems on the market today. So easy in fact that you don't even need to bother with the operating manual. The graphics, screen and layout of functions and controls are impressive.
And... the butt coolers in the seats actually work.