I think that it was a bad move to try to tie the singleplayer story's Galactic Readiness Rating system to apps and the game's multiplayer mode. While the concept sounds alright, I dislike being forced into utilizing multiplayer features or apps, when I would have been perfectly okay with an alternative means to the same end that could have allowed me to remain antisocial. I think that that whole area (galactic readiness) should have been dependent upon the numbers of side quests completed in each region, including DLC, as well as certain war assets and intel which the player can acquire over the course of the game. Those criterion, along perhaps with the outcomes of certain events, like Rannoch, would have done me just fine.
I got the Paragon Destroy ending to ME3, and I feel awful for destroying EDI and the Geth. The genocide of the entire Geth race, whom I had only just got done saving because I recognized that they counted as living, intelligent beings, stings particularly badly; more so given how much they were helping the Quarians to acclimatize to living on Rannoch again. Given my views there, it follows that I should have gone for the Synthesis ending, but I just couldn't bring myself to do it (who am I to force an "upgrade" on all sentient beings in the galaxy against their wills?), and as a result a beloved character and a fantastic race another great character sacrificed itself to save are all dead.
I understand that many things can be replicated and rebuilt, as Hackett said in the Extended Cut epilogue, but with people, with intelligent A.I.s, well, they can't be identical if they're rebuilt. Identical clones with identical programming created after the Reaper War will develop quite differently to those created before. Their lives, the situations they'll be placed in etc, will not be the same, so they will not turn out the same. Maybe that's good, maybe not. I live in hope that perhaps EDI may have secreted a copy of her more developed self somewhere safe, maybe her cyber-warfare suites developed enough to protect her, or that the Geth built another deep space station out of reach of the energy wave in which to house runtimes and programs... but if the Perfect Destroy ending is the one Bioware at least eludes to in ME4 and EDI and the Geth are safe and sound, will it feel like the impact of ME3's ending was all for nothing? I want to think that I got the best ending I could, and in a way I did, but at the same time, I can't help but wonder if another ending might have saved everybody... Bittersweet stuff.