3.0 Duramax or another 5.3 V8?

I'm wondering how many 1500 owners have the 3.0 Duramax and if they like it?

I have a 2018 with 57k and about 1.5 years left on my loan. I am considering trading in for the 3.0. I tow a 8k lbs trailer two to three times a year to TN and back. And have a 80ish mile round trip commute. I can't justify a 2500 so this is my next best option.

I can get 20-24mpg avg on the hwy with my 5.3, however, when trailering or city driving, I am lucky if I get 10-12pmg.

What MPG do y'all get with the 3.0? I know Diesel is expensive, and DEF is a consideration. But I think it might offset based on my use cases.