Didn't bother playing through the end again, don't care enough to so I watched the endings on youtube.
Synthesize
Destroy Ending
Taking Control
All in all, I think the Destroy/Take Control endings are ok, but that synthesize ending is absolutely ridiculously stupid. Still, to end a trilogy like this, it could have been done much better. Your decisions have no impact on the ending at all.
My favorite new one is the destroy because of the last scene in it.