I am glad I read this old thread, I didn't realize how strong and tall the wall is.
I did the DPF delete before I saw this thread. I am not certain I agree with the intense view that you are one or the other.

Deleting the DPF does cause soot to be released, but while burning signifcantly less fuel. Doesn't the smaller fuel burn count, is that not one way to reduce emissions? What is soot anyway? Gas engines use a catalyst to convert carbon/monoxide to H2O. Thus reducing the quantity of vapours being released. So this soot, is it toxic, or just simply dirty? It is not a vapour, it's a solid and visible, so the politicians have jumped on this as an issue. Am I wrong?

Oh, I feel I should comment on the 5.9 vs. 6.7. Yes I had a choice, a 5.9 with a zillion miles on it or a new 6.7. It more than the number of miles on the engine, if you are looking at a high mileage truck, it might run well but often the rest of the truck is beat.