More than power, life expectancy. Diesel is king for power and strength. Diesel costs more than gas, fuel, engine and maintenance, cost more.
I am not familiar with the models you are looking at but all diesels that I am aware of have air suspension, and gas is on springs. There is no comparison in ride, air is much better.
The reason most diesels have rear engine is for noise, it is much more pleasant driving without the engine noise.
This is just imho.
GS 2006 Yellowstone 8356