I'm replaying ME3 again (3rd time, yo!

, and personally, while I do have some gripes with the ending, overall I did enjoy the finish to the ME series in general. Regardless of the outcome, there was always going to be some disappointment simply due to it being the final Shepard chapter. We get emotionally attached and involved with our characters; we hate to watch them die or end in any format.
So, the Destroy ending. Well, for starters, it is my opinion that the kid on Earth -WAS- real, did die horribly by the Reaper destroying his shuttle, and that my Shepard spends the rest of the game agonizing over his guilt by using the image of the kid in his dreams to atone for the deaths of so many individuals. Let's face it, it's impossible to personally quantify millions of deaths at a personal level; but watching an innocent child get blown to dust in front of your eyes, that's going to leave a scar. I actually think the reason that the Reapers/Catalyst are able to use that image to communicate with Shepard at the ending was due to our travel through the Geth Collective; while we were happily running around blasting away at Reaper code, who's to say that they didn't also get the chance to download a copy of Shepard's own personality matrix in order to see what makes us tick.
The final confrontation with the "Child" on the Citadel, I think it's important to remember that the story of the game takes place over MILLIONS of years in game, not simply the three years that ME1-ME3 tracks. The Reapers have been performing their cycle of destruction over and over and over for countless generations; the galaxy has been rebuilding itself over and over and over just to be wiped out each time... until this one. The original race that created the Reapers (let's call them Preservers) had a "master" plan; in order to prevent the galaxy from ultimately wiping itself out, they "reset" the playing field each time by destroying the most technologically advanced races, but sparing those that are not a threat. Granted from an outside perspective, this is whacky crazy logic, but it's also not entirely unique.
I see a great deal of the Vorlon/Shadow plot thread from the Babylon 5 series in the story influence; where we have a group of powerful aliens who value "Order" and control, and who use the act of wiping out and rebuilding the survivors to reset the galactic path. Hell, even the name of Crucible is somewhat telling as its a "reforging" of the galaxy. We presume that the plans for the Crucible are Prothean initially, just as we assumed that the Citadel and the mass relays themselves were invented by the Protheans. But we were wrong in our assumptions.
We find out in ME1 that the Citadel and mass relays were created by the Preservers as tools for the Reapers to travel the galaxy during their cycle. We find out later in ME2 that the Preservers coded the Reapers to reuse the last cycle's powerful species as their servants towards the next cycle (hence, the Protheans became the Collectors), and finally in ME3, we find out that the Crucible had actually been in development for MILLIONS of years before the Protheans did their research, and it is ONLY in our final cycle that the design for the device is completed and built. Once it docks with the Citadel, and integrates with its systems, the "Child" admits that the Crucible has modified its own programming and opened the new options available.
Think about it, the Reaper cycle is -NOT- complete genocide and destruction; it's brutally CALCULATED destruction. It's possible that even the Preservers themselves anticipated and created the Crucible plans to test organic life, and see if their cycle could actually ever be avoided. The fact that the Catalyst is no longer able to perform its normal cycle is a major achievement for the organics, and is even grudgingly acknowledged by the "Child" when you meet.
What's important to me, anyway (after this long-winded rambling, sorry

, is that despite the Crucible making changes to its programming, the core of the Catalyst remains the same. It controls the Reapers; the "Child" is responsible for wanting to continue the cycle of death/rebirth, and even argues with Shepard that taking the Destroy option will NOT bring a lasting peace, and that new synthetics will be created, and the cycle would start over again, yadda yadda.
The Control option results in basically a stalemate of the Reaper cycle; the Catalyst would remain in place, Shepard will die, even the Citadel remains intact for a possible future restart to the whole mess. That's not acceptable to me. The Synthesis option, to me anyway, would be EXACTLY what the Reapers and Catalyst would desire (even the Reapers themselves -are- bio-mechanical constructs created from the organic remains of previously destroyed races). Why the hell would I want to help them achieve their goals of fusing synthetic and organic DNA? Screw that noise.
So, I blows them up. Even -IF- the Destroy option resulted in the death of EDI and the geth, my character personally is okay with that for a couple of reasons. In EDI's case, she's already admitted that Shepard's actions and decisions are what have awakened her humanity, and that she is ready to die if it means the end of the Reapers and the survival of Joker. Both of these conditions are met in the Control option; yes, it is tragic for her death to occur if so, but ultimately no worse a sacrifice than Mordin's in removing the genophage. If EDI was there, I believe she would have urged Shepard to choose to Destroy the Reapers directly.
This is also taking into account that the "Child" is telling us the truth. After all, in the dialogue, the Catalyst is clearly reluctant to see Shepard choose this option. It seems almost an intentional jab for it to bring up the Geth being destroyed as a method of pushing my character's emotional buttons. For myself, I chose to rewrite the Geth in ME2, and later to save both the Quarians and Geth for the final conflict. Ultimately, I would still sacrifice the Geth to destroy the Reapers as it would mean the survival of the galaxy as a whole; the war with the Geth originally wasn't the fact that the Geth were being asked to die, it was WHY they were being wiped out. I strongly feel that Legion itself would have seen the logic of sacrificing the Geth Collective (if necessary) to remove the Old Machines completely from the equation.
Finally, the fact that the mass relays themselves are destroyed SUCKS, but is also completely not unexpected. THEY ARE THE CREATION OF THE PRESERVERS! They were created and used for the REAPERS to travel the galaxy for their cycle; when we end that cycle, why wouldn't their tools be also rendered unusable? It's also interesting to note that in the final cinematic, unlike the Arrival scene where the Mass Relay is charged and active with a great deal of energy at the moment of its destruction (thereby resulting in the massive and catastrophic explosion that takes out a solar system), the energy of the mass relays is instead focused and channeled into the carrier beam that is transmitted to each device, BEFORE the relay itself explodes. Again, this tends to confirm that the Catalyst's duties are ended, that the cycle is completed, and the Preservers foresaw a "self-destruct" plan once the mass relays were no longer needed (from THEIR perspective).
All-in-all, the ending was good, it just wasn't great due to the lack of the expanded information we lack regarding our choices (did we wipe out the Geth, did EDI survive, how did the other races get home, etc). Also, the final scene where we see the old man and child on the planet talking, it's clearly the planet that the Normandy crashed on, and presumably, that would have been Joker talking to one of his grandchildren.