@tsarstepan,
I thought about this for a couple of days. While Firth is wonderful at portraying grief in Single Man, he is, all things considered, a quiet, compressed, minimalist actor. The role was brilliant and the movie well written but . . . with the exception of his decision not to commit suicide . . . the character did not change. Bad Blake changed. I think, on reflection, that Jeff should get the Oscar.
Speaking of change, the lead in District 9, who never made a movie before, certainly handled the change in his character well.