So I finally reached the end of the game...and I loved it. Sure while I understand the gripes with the ending but to me it fits this series perfectly. All three games have revolved around making sacrifices in order to achieve the overall goal. Now as far as the "Child" goes I feel thats left up to the player to interpret. In my mind what we are seeing is simply an AI that was created to be in charge of the Reapers and control their actions. It takes the form of a child because it most likely delved into Shepards mind and realized that child had a profound affect on Shepards mind and then decided to take that form. Remember the child itself says no organic has ever made it that far so why would it look like any other form in particular? It picked something from Shepards own mind that Shepard would recognize as important and be familiar with.
In my game I had over 5k military strength, 100% Galaxy Readiness and all side missions complete except for some of the scanning ones. I was presented with the three options. Destroying the Reapers, controlling them, and synthesis. I chose to destroy them. The crucible fires destroying all synthetic life. The Mass Relays get destroyed in the process (happens in all three choices) leaving the Normandy and crew stranded on an unidentified (to the player) planet. We then see Shepard's body in rubble in a closeup of his N7 tag and in the last seconds Shepard's chest moves which looked to me like he breathed, or in other words he survived. Credits roll to final cutscene of an elderly man telling a little girl about the Legend of Shepard. Hearing the end of the Reaper story the girl asks for one more tale about Shepard and he agrees to tell her one more story, again confirming that he survives. Last thing is a piece of text from Bioware saying something along the lines that Shepards tale will continue in the future with DLC, etc which makes three confirmations that Shepard survives in my book.
Do I understand the complaints? Yes. Do I feel like my choices mattered? Yes. Am I happy with the ending? Yes. Would I have preferred a total "happy" ending? Maybe, but maybe not and maybe we will eventually get one.
All in all though I applaud Bioware writers for having the balls to go with a risky ending. They could have simply ended it with the Reapers being destroyed and everyone goes home for a cup of tea and hot love making but they in my opinion stayed true to the core of what the series has been about and offered up three huge bittersweet sacrifices as your final options.
I know my opinion isn't a popular one, but I sure as hell enjoyed this game and enjoyed the ending. And the way I see it any ending where someone somewhere survived is a good ending versus the Reapers. And seeing that Shepard survived through it all and we will most likely have DLC or more games furthering the story I see this as far from a bad ending.
Just my 2 cents.