I know Jo has a soft spot for Sirius, Taulai. I began to suspect it while reading Goblet of Fire for something like the third time last summer. She has a way of describing him that never gets passed on to any of the other characters. Ah, well, **clicks tongue,** who am I to argue?
**Sigh.** Poor, poor little Remus. Another standing difference between him and Sirius is that Sirius is very, very vital. Even with being locked away in Azkaban for years, he's still retained enough of his personality (humanity, maybe?) to laugh, to be a vindictive jerk, to weep ... But Remus; it's as if his softer qualities have been burned away by years of grief, and now he's just left with scholarliness and solemnity and a certain feeling that he doesn't have anything else to live for. Maybe now, with Sirius back, he'll be a little better off ...
Nah, it's just that much more likely that he'll throw himself into the fire in Sirius' place if he gets the least chance. Whereas Sirius just projects this air of being a lucky bastard who'll always escape death at the last minute because he has something else to live for.
Damn you, Remus, stay alive or we'll never forgive you!