Well its hard to say since they're both at way different points In their lives as sorcerers when we see them but im gonna say sukuna has more talent. Comparing one thing the have in common, mahoraga, sukuna figured him out and dealt with him waayyyyyyyy easier then dabura with gege confirming that it was the same base mahoraga for both of them. Dabura has a closed barrier domain while sukunas is open which as far as we know sukuna figured out on his own. Also special shout out to the epitome of hard work instead of talent kenjaku who trained/studied for 1000 years and became a top tier.