I'm gonna give it to Worf even though he's somewhat trigger happy (after all, that proved to be a set up anyway). If the question was who is a better Commander of DS9, that would go to Kira. But the only person better on the Defiant's bridge than Sisko is Worf. It's a badass fighting ship, no diplomacy, no exploration, just shoot. That's got Worf's name written all over it.
I totally agree with you.
Sadly, I voted before I read the OP.
I thought the poll was about the DS 9 station, not the Defiant, so I voted for Kira.