@Fezick, it sounds like you really want the diesel, so I'd say def get it if that is what you want. Only way you can know is buying it and living through the ownership process to see if it's a good fit or not.
One thing I'll say though, is that slow speeds and idling are generally what cause issues with modern diesel trucks. At lower RPMs you're going to see more soot load on the DPF in part due to turbo only kicking in so low. That excessive soot load will show up as more frequent active regens vs fewer passive regens. This may eventually turn into a bit of a spiral as the excessive soot load will start to cake the grid heater, which will in turn reduce the amount of air getting into the cylinders, and less air means the fuel won't fully burn, so thus more soot. It's slightly more complex than this, but suffice to say, idling is not your friend, and slow speed offroad or around town trips are not your friend.
Since you're in cali I'm assuming you are used to "longer" highway trips, so just make sure that you get on the highway and stay at speed for a bit every so often. That will help keep the systems clean and functional.
One final comment here. You seem to be concerned with resale value of the truck, as that appears to be one of the driving factors for why to purchase the Cummins over the hemi. I'll admit I don't quite understand this reasoning. While a diesel truck will hold a slight benefit over a gasser in resale, you should consider a few things.
- A diesel is higher upfront cost, and so while you may get most, or even all, of that back by selling it, if you're not paying cash you're financing ~10k more, which means roughly an additional $1500 in interest
- A diesel has higher maintenance cost, and while it's somewhat offset by less frequency and better MPG, it's still higher
If you're primarily concerned with what makes the most financial sense, perhaps look at a few year old used diesel, as it will have taken the majority of the depreciation vs new. Again, if you really want a diesel, and you really want new and have the finances or are comfortable with stretching your budget or whatever, then by all means. It's your money, life, etc. you should be happy and a bunch of dudes on the internet can't change that.
If you do decide to move forward, I'd at least wait until the new Cummins truck is publicly officially announced. At that point a lot of folks will wait for the ZF because of the hatred for the 68rfe. If you can wait till the new ZF starts hitting lots, and are willing to be flexible with options, that is where you'll likely see your best savings new.