Have experience with pretty much all 3 of them. Had a 2020 5.3 10 speed. Currently have a 2022 3.0 10 speed. Also have a 6.2 Camaro. So not exactly the same, but close enough.
Originally went with the 5.3 over the 6.2 in the 2020 for a few reasons. First was because it is my wife’s DD and our tow vehicle. She isn’t a huge fan of driving my Camaro. Too much power for her. Second was because it doesn’t require premium gas. Already have that with the Camaro so didn’t want to have to run premium in both. The 6.2 seemed to be the only engine with the lifter issues at that time too so that squashed any urge to go that route. Also the 3.0 wasn’t an option in the TrailBoss at that time.
When the 2020 got totaled the 3.0 made the most sense. 6.2 and 5.3 both took a significant gas mileage hit and are subject to the lifter issues. We all know the tank size doesn’t favor those who tow so while the mileage hit may not be that big a deal to most it mattered to us.
Got a 2022 LTD 3.0 TrailBoss about a month ago that is nearly identical to our 2020. We have been pleased with the 3.0 so far. There is pretty much no noticeable difference between it and the 5.3 performance wise except for the diesel sound. Have gotten over 26 MPG on some highway trips. Haven’t towed long distance yet but got 12.5 mpg in the city towing our trailer to and from storage. The 5.3 got around 10.5-11 on the highway. Like someone else said they all have their place, but I’d recommend the 3.0 to anyone interested.