I have owned 2 diesel trucks, a Ford and a Ram, plus a 09 Jetta TDI. I love diesels. But they are not good for very frequent short trips, which is why I sold my Ram to get the Jeep. Maintenance costs for regular stuff is more expensive than gas engines. Fuel prices have been all over the map the last 7 years. And most turbo gas engines require premium fuel and the MPGs are not that great in real life. Audi and Ford come to mind with that.
Now, if you modify the diesel engine and void the warranty, that is a whole different situation. It sucks but the EPA standards forced the engine makers to come up with quick fixes and it is slowly getting better. The DPF is not a bad design, but the extra fuel injection sequence for a REGEN causes fuel dilution and that is bad. This was the problem with my 08 F350. The UREA is great, until it freezes or the vehicle goes into limp mode because the UREA, or DEF, or AdBlue, depending on the car maker, does not have time to thaw to complete a required REGEN. But the use of DEF does eliminate the extra fuel injector sequence and therefore no more fuel dilution.
I am not a tree hugger and I hate the EPA. That said, I am all for having lower emissions if it makes sense. I still cannot figure out how an old 5.9L Cummins in a Ram 3500 4x4 could get 28 MPGs on the highway in the 90's and today's 6.7L with all the technology is lucky to get 20 MPGs. Or the old economy cars like the Cavalier or Carollas from the 90s could get 35+ MPGs on the highway and today we are no better with all the technology and more aerodynamic bodies.
http://www.fueleconomy.gov/feg/bymodel/1998_Jeep_Cherokee.shtml. I only get 3-4 MPGs more than a 98 Cherokee 4x4 with the 4.0L.
I have said it before, I would be in a Grand Cherokee diesel if Jeep did not decide to rake a buyer over the coals without any lube. One day I will have a competition diesel truck that I build, but it will not happen until after I become a grownup again
**I forgot to add, in my Jetta I averaged over 48 MPGs. And never had an issue with it. Awesome little car, even in the snow so long as it was not too deep.