Ive always been a "GM guy" however not brand loyal. My brother in law does have a 2020 chevy high country 2500HD I can tug the boat around in some time, we have a 2021 F550 and its been amazing the short time we have had it probably shouldn't compare 250 to a 550 though haha
No experience with the cummins though, did sit in one and it was nice however I wouldn't call it "better"

The short time I've been shopping the way I see it

Ford- 475hp-1000lbtq- 10 speed. EVERY OPTION (in a platinum) $79K

GMC/Chevy- 445hp-910lbtq- 10 speed (Fords right?) No adaptive cruise control or massaging seats. And I Love adaptive cruise. Denali price is like $83K

Ram- 410hp- 1000lbtq- 6 speed (ancient tech) No massaging seats. I have no idea about the trim levels but the limited is also right at $80K

Correct me if im wrong or missing the big picture on anything I haven't shopped big trucks in a long time