I'm sure i wrote that somewhere else before, but whatever you choose (and shep is forced to play god, because he has to choose the fate of the entire galaxy and his decision is forced on every beeing, no matter what), it's just peace or even a good end for the moment, but not the long run.
The endings remind me of the Descent: Freespace Series. Whatever you did, you survived by sheer luck or because the shivans decided to let you live, but always had to pay a big price or make a huge sacrifice.
...
The thing is that Synthesis will absolutely not be the default ending or the canon ending going into ME-Next. It can't be. Why? There is no conflict. You can't have a story without conflict. ...
Synthesis does not only changes organic life but synthetic as well, giving them the ability to feel and think what life really is. It's struggle. Only the strong will prevail and survive. And who are the strongest? The Reapers after all. Synthesis is just the end for the everlasting synthetic/organic conflict, but not the end of all conflicts to come. Civil war has happened in every organic civilization before and as sson as the reapers realize, who has got the power, it certainly will start again. But this time for extinction, not preservation, cause all are equal in their DNA now. but there is a glipmse of hope that they won't do it.
It is the most paragon solution imho, one sacrifice to safe them all.
Control keeps a part of you, your memories intact.
And Destroy, genocide for all synthetics.
But if you pick destroy, do you really think the survivers of this war are capable repairing the mass relays?
The Protheans where on the brink of unravelling the mysteries, but we are not the Protheans.
Most major planets are in a bad shape, decimated population, most industry centers laid to waste, armies shattered.
I for myself doubt that. That's why i chose synthesis, although it can never be canon:
"Who dares to enter our realm... we've got the Reaper Keepers on our side!"
Not a chance.