Wvu, you're overthinking it, IMO.
Did you think the same about your Lily Duramax when you bought it? Becasue intercoolers, overheating and injectors were "issues" with them.
You literally do not have more to worry about with a new diesel than the old one in your driveway. If you were talking 08 up to about 2013 I'd have a different answer.
Of course buy what you want, but financially, if your 05 is in otherwise great shape, you're money ahead to run it, even if you do sink a few grand into preventative repairs.
The Internet is good and bad. Now everyone has 1000% more things at their fingertips to worry about!
Gas trucks aren't magically problem free either. Most all new trucks ARE pretty problem free, but example my 2016 Silverado. If it was newer it would have been out of warranty when it spit out a bad transmission at 60k miles, without warning and with proper maintenance. I could look at the flip side and say if it was an Alli behind a Dmax, it wouldn't have happened.