If anyone's interested, I have found what seems to be a crucial technique for great baba.
In Nancy Harmon Jenkins' book The Mediterranean Diet she instructs you to use a mortar and pestle to create a paste of salt and garlic, and then incorporate this paste into the mashed eggplant.
This is the kind of small step that I used feel free to bypass out of laziness. (Oh, just mince it up, what the hell. I don't have/can't find/haven't washed the mortar and p.)
I was terribly, terribly wrong. Having done it her way the last few times, I think the salt/garlic paste somehow releases and distributes garlic flavor like nothing else.
I used to think that the key was just that the eggplant be grilled/roasted, and not pan-cooked. This does matter, for the char flavor. And the rest of her recipe is pretty standard. But this garlic/salt business makes all the difference.
(Personally, I like incorporating a bit of real Greek yogurt as well. Highly unorthodox, but there it is. If you're only fork-mashing the eggplant (as opposed to chopping), the bit of yogurt gives the dip a nice foundation of smoothness, without undercutting the texture of the eggplant. Not to mention the bit of tang and creaminess it also imparts.)
Her book is also very useful all around, despite the title which makes it sound more like a diet fad than a real cook book.