The thread is not even 24 hours old & page 3 already. Must be winter. I'll bite.
My answer is, it depends. If I was a weekend warrior doing short hop trips to the local CG I guess I be happy with gas. I am not. I usually do something over 15,000 trailer miles a year. I figure on $2500-$3000 a year on truck maintenance including the oil & filter changes. It gets nothing but the best. Over the years the bulk of maintenance has had nothing to do with being diesel. Biggest engine replacement part has been a radiator. The rest has been stuff like steering bushings, tires etc.
There is no real better. It depends on the application.