What trim level is the truck? Do you have lower body side moldings and, if so, woodgrain or black?
If you don’t want to paint the letters, I’d definitely go with the band if you have lower side moldings - and match the band with whatever the moldings are, ie black or woodgrain. Keep in mind that a black tailgate band was not a factory option, they are just making them now along with the woodgrain ones if someone wants a black one instead of woodgrain.
Unpainted letters look unfinished to me personally - but you see a lot of them out there like that. Just personal preference. If NO lower body side moldings - that would be the only scenario where i would go the no band, no letter paint route. But I’d still paint the letters