At 100,000 miles of driving, the diesel mpg saving will have paid for the added cost of the diesel/over/gas decision.
During that 100,000 miles of diesel, the driver has the luxury of power.
For an unfortunate few, diesel downstream maintenance and repairs can quickly eat and possibly exceed that savings.
The upside of the gas engine is their remarkable low repair and maintenance bills.
The downside of gas engine, is of course, lack of power compared to diesel.
"Driver fatigue" is also heightened by a loud engine noise and wind noise.
Caveat: the 100K miles is dependent on driver technique which can vary by as much as 30-percent between divers.
So there you have it...
Best of luck in your decision.