For all around "goodness" usefulness,good mpg, versatile, moderate towing(they have pretty spectacular tow weights), reasonable buy price, and as they get older-ease of DIY work,and relatively inexpensive parts-
It is VERY HARD to beat a 5.3 with that 6 speed AT.
with discounts/rebates etc you can probably find A 2WD one for as little as $25000-MSRP will be much more of course-4x4 maybe $2500 more.The only real competition is the Ford with the fancy turbo charged 3.5 V-6.
The Ford has very good numbers-slightly better EPA FE, better HP, better Torque numbersBUT
1)It is pricy
2) It will be tougher to work on with that turbo
3) Cost more to repair because of that turbo and "busy" engine bay.
4)Long term reliability-who knows?

In the late 70's early 1980's there was a gas price crunch-maybe companies went to smaller spark ignition engines with turbos to improve FE.
It didn't work out very well-the turbos weren't reliable-One problem was the turbo bearings went bad because the heat would "cook" the oil-probably other problems.
Now Turbos aren't new technology-airplanes have used them with gosoline-spark motors) for 70 years- but airplanes are maintenance intensive(expensive)- big turbo diesels have used them for 60 years or so.The Europeans have used them extensively in their 4 cyl TD little cars for 35-40 years-Ford has plenty of experience using them in small TDs

Ford had plenty of experience building 3/4 1 ton diesel pickups-TDs- BUT they had lots of reliability problems with their 2004 6.0 TD- problems weren't with the Turbo, but they had plenty of problems.

Same old story-don't be the 1st to buy new technology- new model year. I would wait several years to see just how well those

All around long term "goodness" hard to beat the 5.3(wouldn't bother with the 4.3 or 4.8 unless you need the lowest possible buy price-which is a pretty good reason sometimes).Really stunning that they now get such good 4X4 mpg-

Charlie
PS My 1998(218,000 MILES) Suburban 5.7 2wd-averages 21 mpg on our trips to Flagstaff AZ and back(FROM NEW ORLEANS- 141 gallons 3010 miles-this is with a hitch basket(in the aero shadow so doesn't hurt FE much). It is rated 12/17- so a 21 mpg(hy) pickup will get at LEAST 21 mpg at 65 mph. I probably average 60 mph on our trips-I set the CC to 67 mph but drop speed for road work, towns etc.
Driven reasonably the 5.3 is very FE.

PPS-the 13/18 must be a different motor- or ???