I didn't want to hijack the other thread on the OP looking to get his first diesel. I bought my first ('14 Ram Mega 4x4) diesel in December and love it. I do see alot of posts about deleting this and that on diesels... I'm a long time very experienced gas vehicle person (nut & bolt rebuilds), but new to diesel. In the gas world you still have folks that recommend against converting a carb vehicle to Fuel Injection for all the reasons one might come up with, which all really end up being about the talking head not understanding Fuel Injection, and being much easier to throw a rock, than learn something new.
My questions are not about performance, I get various modifications and deletes when looking to increase performance. For the average owner (not hauling a 12k trailer weekly, etc) and for say model year 2012 and above, not Mfr specific (trying to learn something about diesels, not why a PS is better than my Cummins) what and why do you recommend deleting something for general driveability and maybe a mileage increase? I'm really happy with my 370HP-800 ft lbs torque and want to understand why I should change the system my engine mfr designed?