I got one good attempt left at a thoughtful comment before sleepy-time, I'll give it a shot.
If you think my opinion of Dax the symbiont is shifty, I'm either doing a horrible job explaining it, or you simply disagree with me. Judging from the fact I have to constantly correct my own typos, I'll assume the former.
Neither of us can possibly understand Dax's motivations. Give me a reason other than it lives inside humanoids that would suggest we have similar motivations.
I provided several hand-picked examples of Dax's reckless behavior that support my view of it. Give me a little credit where it's due.
Jadzia didn't jump in bed with Bashir because he was what, 25, and Dax 'stopped counting at 300'? I had better luck in my 30's than I did in my 20's, I'd like to think a little life experience makes a person more attractive. Jadzia Dax clearly thought Bashir's advances to be a joke initially, but maybe living and working together for six years has the effect of changing that. Even though they eventually got together if you count novels as evidence more than a little heat between the sheets, they still broke it off.
Although neither host got 'the best of both worlds', Dax sure did. It got to reject and hook up with the same person with no repercussion. What a great learning experience.