"worth it" is subjective... Do you mind explaining why you so definitively claim that the 3.0L isn't "worth it"? By your logic, I could claim that the 5.3L isn't "worth it" for most people when compared to the 2.7L or 4.3L. All of the engines that are offered have their strengths and weaknesses.
When comparing the two engines for this discussion, I see the following:
For the 3.0 (all of which cannot be argued)
Superior fuel economy
Slightly better towing (possibly not max weight, but I will quote what you say above, "it will pull like a freight train")
Quickness (although this doesn't matter to me and presumably most truck buyers)
Range - both come with a 24 gallon tank
Against the 3.0
Cost (subjective... a lot of unknown variables)
DEF - next to nothing
Cost of fuel - Diesel v. Gas - fluctuates... and in my area the spread isn't large. E.g. filled up yesterday for $2.38 v. $2.18 for regular unleaded
$2,500 engine option over the 5.3L - again based on the above I doubt you can make an argument that spending $2,500 extra is or isn't worth it in the long run
New engine (reliability) - as I mentioned in another thread, who has a crystal ball? Am I an idiot for taking a chance on a first year engine? You have plenty to worry about with your amazing 5.3L as well. You act like nothing has changed to the 5.3L over the last 20 years
Maintenance costs - again, subjective at best. Will the 3.0L experience major emissions issues? what about the wet oil pump belt that has to be replaced every 150,000 miles? How will this compare to the 5.3L?
I am not trying to argue and truly believe the 5.3L is a great engine... Simple minded me just doesn't understand how you can so quickly write off the 3.0L? I would greatly appreciate your insight as to how I am wrong. For now... BYE BYE 5.3L, HELLO 3.0L