The oil pan is the only common issue. They originally just did it with rtv like most axle covers and if the factory wasn't perfect they started leaking. The dealer had to let it completely drain (usually pan off overnight) then clean it completely with the proper product then apply the rtv correctly and allow it to cure completely (several hours) before filling with oil and running. Fail to follow instructions to the T and it would be back.
The newer pans now use an O-Ring which should eliminate the issue.
I had a '15 Gen 1 and had no issues even with my 6500 lb enclosed car trailer, however be aware the 2.7EB is rated about 400-500 lb lighter GVWR normally. I needed the 7000 GVWR when I bought my '18 and the 2.7 Payload Package is very rare on the lot and very limiting in trim level so I ended up getting a 3.5EB this time.
I actually found the 2.7EB more entertaining to drive. They are more responsive and quicker for the first 1/8 mi. After that the 3.5EB will start reeling it in.
If you drive extremely conservatively it's possible to break 30 mpg highway with the 4x2. A friend's dad got 28 mpg one way and 27 mpg the other cruising at 70 mph from Huntsville AL to Charlotte NC and back with a Gen 1. The Gen 2 does slightly better on fuel.
The nephew has a Reg Cab 4x2 XL 101A Chrome Package with Gen 2 2.7EB, 10R80 and 3.55. Anyone that thinks that little engine can't fly needs to drive that truck. It runs 8 second 1/8 miles bone stock.