Here's some thoughts of mine (and others) from a previous thread, revised and expanded to make it more fitting for this thread:
Jadzia, seemed to act rather arrogant around anyone who tried to make advances toward her. (Bashir comes to mind, but also Worf--"You thought I wore this for you...talk about overconfidence!") The irony is, she seems to constantly make efforts to
put said men in those positions (the "outfit thing" with Worf, for one, and massaging Bashir to "prepare" him for the Altonian Brain Teaser, for another).
It's almost as if she's trying to revel in her "power" over men.
Ezri has no such power-lust. In its place is an almost child-like enthusiasm and mischeviousness.
She's bubbly, perky, fun and has that girl-next-door quality which a lot of guys find attractive.
While Jadzia's sense of humor is more dry, Ezri's is more playful. Jadzia seems to emphasize her maturity--"I was young once, so I know how it feels...." Ezri
acts young. She's youthfully innocent, almost to the point of being eccentric.
In regards to Ezri, it's also her attitude. Her attractiveness is understated and it's almost like she's not trying but can pull it off.
When you get down to it, Ezri seems more "unintentionaly" feminine. (i.e. She doesn't
try to drive guys crazy, like Jadzia.) When Bashir (in "Exreme Measures", when he "wakes up" in the Infirmiry to see her standing next to him) says, "Ezri...you look so...beautiful....", Ezri looks stunned, and then she stares at the ground and smiles.
While she can be feminine (sometimes disturbingly so), Jadzia's more of the "tom-boy" type (for proof, just ask yourself if Ezri would be comfortable in a Klingon uniform....). While Ezri can handle combat reasonably well, her one-girl rescue mission to the Badlands showed her as kinda out of her league.
She's a lot gentler, too.
Ezri's my vote.