Yeah he has a dark side, as he's always had, but I don't think I would ever characterize the Doctor as "malevolent."
Certainly not Smith's Doctor, who at heart seems to be one of the gentlest and kindest Doctor's there's ever been.
Agreed. Smith's Doctor is certainly less prone to righeous fury, certainly when compared to Eccleston in "The End of the World," "Dalek," "Bad Wolf," & "The Parting of the Ways" or Tennant in "The Doctor's Daughter," "New Earth," & "Waters of Mars." Tennant, for all his goofiness, even had some surprising moments of cold blooded vengefulness, like "The Family of Blood" & "The Christmas Invasion." ("No second chances. I'm that kind of man."

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As was said before, I can just as easily see the 6th, 7th, 9th, & 10th Doctors doing the same thing the 11th Doctor did in "A Good Man Goes to War." In fact, I can pretty much see any of the Doctors doing that if pushed that far, although perhaps some of them would be far less inclined to involve anyone else in the rescue effort. (Of course, the 1st & 2nd Doctors were deliberately trying to keep a low profile. And the 4th Doctor was the biggest loner of any of them.)