I have a '14 Grand Cherokee Summit with the EcoDiesel. Sitting outside right now with a hair over 85k miles on it.
LoveloveloveLOVE it.
Couple warranty issues but nothing that Ma Mopar hasn't taken care of (at least, as quickly as parts are available). Most of the diesel issues center around leaking EGR coolers, but caught early enough they don't disable the vehicle so it is still usable while parts are on order. I've also had to replace 2 front hubs and a steering rack (noisy, and leaking - not unusual Grand Cherokee WK2 issues)...but that, and 2 EGR cooler replacements, are the sum total of my warranty experience with this Jeep (aside from the emissions flash debacle). They issued an EGR recall right after my last replacement, so I'm waiting to see when/if this one starts leaking before I go putting a(nother) new one in, especially since my last replacement IS the recall kit, anyway. It's just another freebie in the bank!
I don't plug in the block heater, even in single digit temps. It starts and runs fine.
I don't add any snake oil to the diesel fuel, even in silly-cold weather. No gel problems. Starts and runs fine.
I use pump DEF from the truck stop - significantly cheaper than store-bought, works fine, I fill the tank (literally) once a year.
I change the oil once every 10k miles. Zero issues, zero consumption, factory interval.
I change fuel filters every 15k miles. Zero issues.
I keep it BONE STOCK. Stock exhaust. Stock filters. Stock emissions.
I average (in ***-cold winter weather like now) 24mpg winter time, 27mpg summer commuting (local/mountain driving). Highway, like driving from MD to FL? 32mpg, all day long. 5500 lbs, all wheel drive, luxury SUV.
Revs like a gasser. Accelerates like a gasser. Torque for DAYS (stock in my '14 is 240hp/420tq; the new ones are stepped up even more than that). Clean. Quiet. Efficient. Durable. LOVE IT.
People will give you a hard time about "diesel prices" - screw 'em. No tuneups. No spark plugs. Dollars a gallon may be higher, but...dollars per mile? MUCH cheaper overall.
My debate is honestly whether or not I'll ever mess with it. My work truck is my '01 Cummins Ram 2500, 24v, 6 speed stick, 4x4. Edge Comp box, open air intake, Banks 4" turbo-back exhaust, upgraded manual lift pump, boost/EGT/fuel pressure gauges, and a South Bend clutch. 289k miles; I replaced the clutch at 250k. Boost is cranked up, turbo spools fast, it puts plenty of power to the wheels with the box on it....but I just don't feel the need to do that with the Jeep. More power is easy with a diesel...but I love the reliability on the Jeep and I just don't think I'm gonna mess with it. It doesn't need it. The Cummins is dead-nuts reliable too...but those ISBs are so under-stressed in the Dodge chassis to start with, it's only just starting to realize some of its potential in there. I need THAT one to be reliable, too - it's my business truck for my concert company, so it has to get to shows when I need it. And, it does - at 20mpg all day long with my concert rig on board. But the Jeep...it's just gonna stay stock, reliable, decently-fast, nice and quiet...and comfy.