Having owned a few, I would say quite often it's a wash. The reason I want another diesel is for towing and not feeling like I am spewing raw fuel out of the exhaust pipe and stopping every 300km to fill up. Also I want a truck that doesn't exhibit the transmission hunting to find a gear on hills while towing which helps have a feeling of confidence.
Ten years ago it was black and white. Diesels ran longer and had better fuel economy bar none. Now, with emissions, the fuel economy seems to be less (although coming back up slowly as technology gets better) but also there is some growing pains with emissions. It happened with gas engines in the 70's so now it's diesel's turn.
Now, the big three have gone beyond what a lot of us need or want. I really don't need the bragging rights of 1000ft/lb of torque and 14mpg but it sure seems to be heading that way. Now, you will find forum posts where people are getting 21mpg with a Powerstroke or a Ram Cummins but the trucks I have been in with friends or work acquaintances show a different real world picture to me.
I am definitely one of the "white spacers" Nissan is targeting with this truck/engine combo...
Now, what the Ram Ecodiesel did to me was get me back interested in owning a diesel truck primarily due to the fuel economy but I just can't find the gusto to pull the trigger.. When you hang around the Ecodiesel forum, the engine still has some growing pains that FCA seems happy to let the customers suffer through instead of making large changes to address them. This is where Nissan has a window.
Make this engine bulletproof WITH the emissions and allow for some impressive fuel economy when empty...Like 21 to 23 MPG combined would be enough for me to pull the trigger.
Sorry for the brain dump but I figure there might be some first time diesel owners the new Titan will attract that could benefit from an honest view of the Diesel pickup industry
M1lks
on edit: Also what Nissan/Cummins was smart to do with this truck was not making it so that this engine needs to run fancy oil. I read an article that I can't seem to find this second that said that was one of their goals. This is an important issue when weighing cost of ownership is definitely the cost of an oil change. Back in 1991, I owned a Ram with a Cummins diesel. Now that truck had 150hp and 400ft/lbs of torque and I used to pull cars around the Province. The oil change interval was something like 12000kms however it took 12.5l of oil if IRC. An issue I see with cost of ownership with the Ram Ecodiesel is oil changes are $300 and you need a special european spec'd (which will become better and hopefully cheaper as time goes on) but that is a big cost of ownership considering my Ford Ecoboost I run currently for work runs about $90 for an oil change/16000kms on average all in. (All prices CAN$)