Actually, I think Obito being Tobi was the best choice. He actually is connected to the character living today, which adds a bit of a intriguing tension to the battlefield and it gave Kakashi some wonderful character development. Also Kishi is pleasing two different fanbases; Madara represents the arrogant villains that do it for the lulz, like Deidara, Hidan, Kakazu and Orochimaru while Obito represents the villains that were once the good guys, but turned evil due to a traumatic experience like Nagato, Gaara and Sasuke.
The only thing that Kishi messed up on was his backstory. I say this with caution because Kishi might not be 'done' yet with this character, just like Itachi and Nagato's full history were explained after their battles were done.