I have a 2016 5.3, 3.42 truck. It does well for what it is.
Yes, occasionally hook 10k plus and typically pull over Snoq or Chinook pass.
Reliably? Truck has 85k miles. Had it since new, only "early maintenance" has been shocks and struts around 60k. And brakes wore out about the same mileage. But this is a company truck, work truck so it gets used like a truck or at least for the first coup,e years it did.
Reliability? Trans went out at 60k under warranty. Torque converter something let loose which fouled the valve body. Warranty ended up replacing transmission, but the dealer was not too competent. Maybe due to how I used the truck but I think there was something wrong with the torque converter from new. It always had an odd shutter when taking off with a load.
We have a fleet of the same or similar trucks from 2016 up. Mostly all old body style. 4.8s and 5.3s. Many approaching 100k lime mine and no other major repairs that I'm aware of.
AFM is seamless and hasn't been a problem on the newer ones. Older trucks we've had issues with it.
I've driven some of our trucks that don't get "worked" hard and 60-80k they drive as tight as new. Mine drives great still too but I can tell the subtle differences of being worked.
I wouldn't hesitate getting one for your use, unless you're towing 50% of the miles or more maybe.