Quote Originally Posted by Rex_Pelasgorum
Howewer, if you wait for them to sally, they will be extremely vulnerable....
Yes, that's part of what I meant when I said I would rather starve out the AI than assault a well defended stone walled city. I have not worked out what determines whether the AI will sally at the end of a siege - sometimes you get the city without a fight, sometimes they sally; I haven't worked out why.

Sally may be decent when you have numericall superiority, or good troops, or some reinforcements, or anything... otherwise, even if you try to get out of your city and kill the enemyes, you will have terrible losses...
If you go out the front door but are outclassed, the AI may charge you and press you against the city walls before you can deploy. That's nasty (although very characterful). For safety, I tend to go out a side door to get time to deploy. That turns a sally into a regular field battle, albeit with you as the attacker.