After completing the game the first time, I actually went online and read the original leaked ending (by the previous writer) and the ending was more or less the same as far as I can remember, but with a little more clarity. That ending would have actually been fine if they hadn't fed us all the BS about our choices affecting the ending. Had they marketed this game like any other game and didn't put so much emphasis on the save games transfer and choices affecting the game and ending, they would not have nearly as much negative and extreme feedback as they currently have. Even if they somehow removed that quick choice at the end of the game to have it somehow locked in based on your decisions thus far, that would also have dampen the critics... but that quick choice at the end though of "choose your own ending" similar to Deus Ex, is basically an insult to this game.
Besides the last 10 minutes, I was kind of disappointed with the impact that some of the choices in the previous games had. It has been a while since I've touched ME3 so I cannot remember everything, but the Rachni for example... Same gameplay regardless of your decision... they simply added some dialogue to explain how the heck the Rachni got there after being destroyed.
With ME2, you probably had to do at least 5 or more playthroughs to get most of the combinations of choices. In ME3, I've done 1.5 playthroughs and I think I've covered most of it.
The 0.5 playthrough I've stopped just before the Cerberus mission... I couldn't stomach playing through all that last part again knowing that it is exactly the same as before... So I'm exactly where they recommend we start playing the game from for the new DLC.