Both engines are still fairly new, so we can’t tell yet.  For a work truck, I generally prefer gas over diesel (unless I absolutely need the towing capability of the diesel) as repairs can be much higher on diesel over time;  also for those diesels it’s good to make money with it to pay for those very expensive repairs.  Also, I would option them with as few tech as possible to keep the price down and therefore fewer things to break - only get the ‘packages’ you absolutely need.  To be honest, if I wanted a Chevrolet/GMC HD I would get an older one with the gas engine that Scotty reviewed below:  those seem to be true and tried.  And again, I would also get those with fewer option packages ticked since GM is not known for their electronics (esp. over time):

https://m.youtube.com/watch?v=-tc7aG4WifI

https://m.youtube.com/watch?v=xaUuMqCcMkQ

They're only a year old so ....