I chose "destroy" at the end. The result was Joker, Tali, and Javik getting off the normandy. Tali makes sense to me since I romanced her in ME2 and this game. But Javik? I barely talked to the guy... I would have preferred Garrus :/
I went back and chose "synthetic", and the outcome was Joker, Edi, and Tali. So far, that is my favored outcome, and I am about to do "control" next, but I was just curious if anyone had figured out what determines the end characters.
Another thing they need to do is clarify what "synthetic life" means. I thought it would mean all forms of computer intelligence would die, right? That would hurt civilization the most I think... Thus, a good reason NOT to choose "destroy".