I honestly dont know.
At this point I dont know if I want to even replay the game again, and thats not to say Im disappointed or mad, I truly loved it. I beat ME and ME2 close to a dozen times each, but now that I know its over, completely and truly, I dont know if I could to return to it since theres nothing to look forward to, the galaxy I know and love is gone forever even if many of its various inhabitants still survive. The Citadels gone, the Relays are gone, Shepards gone. The entire Citadel society that I became immersed in over 3 games is gone forever and it just makes me sad and I dont know if I want to see that all die again.
I dont have a problem with the endings in it of themselves, but their implications are so far reaching that I cant help be depressed because there is no way I'll ever have another journey in the ME universe that continues the story. Any likely sequels will be set so far in the future with so many dramatic changes to address the endings they'll likely be almost unrecognizable.
As for people hating on the ending and the purpose of the Reapers and all that, I can see why they have a problem with it, I though am fine and content with the Catalysts reasons for their existence and practice, but I think it would have been a smart move by BioWare if the Catalyst had explained that the Reapers had become progressively extreme in their undertaking over hundreds of cycles becoming absolutely brutal in their execution and now with the Crucible and Citadel combined Shepard had the power to stop them but still had three choices, trust the Catalyst and "fix" the Reapers, who would then "preserve" all of humanity in them for all time and continue the cycle for future species to come about, control the reapers and use them to create a new galactic order or destroy them outright and let the races of the galaxy decide their own future.