Regular Sam can be confident and purposefully powerful *when he's alone with a woman*
I think that's very interesting. It's pointless to wonder if that's Jared going "Well, now it's SEXXXY time not that rough stuff" and not having a continuous characterisation from Sam, since it's canon, and that's Sam. And it's also kinda rough in that HOT way (Wincest porn must be *full* of him manhandling Dean, mustn't it? I got the impression that he's usually the aggressor, whether for size coding or easing up on the predatory nature of parental figure incest or just because we've seen him be good at it...the snippets of Sam/Jess I've read have been sweet or romantic or playful but not as hot as Heart, f'rinstance--jesus, that was an awakening...) anyway.
I've been noticing recently at the end of any exertion, Sam does this sort of gasping .. I don't know... thing where his pecs look like they're almost parallel to the floor as he inflates and deflates the gigantic bellows that form his rib cage and his shoulders roll back a bit as he regains his calm. I'm oddly in love with it.
Dean, on the other hand, is not smug about it, but he certainly knows exactly how good-looking he is.
He can't. HE CANNOT. His brain would explode or he'd spend all day looking at himself in the rearview mirror. In fact, I imagine that's Jensen's entire life when he's not acting--exploring or adoring himself.
I would say he knows he's hot enough to get most of what he wants, but if someone were to rhapsodise over his looks he'd get awkward and have an attack of the insecures and the not-importants. I think he thinks he's a good looking guy, but I also think he probably figures he pulls so well because he's a stud...that he overvalues his playerness when, really, most women are like "One night? With that face, and that ass, and those arms? Please god, don't say something too stupid or offensive and make me wake up from this dream early."
The idea that someone would look at him and think "You're kind of a good guy--sweet and brave and good, and YOU'RE BUILT LIKE A BOWLEGGED HORSE-RIDING GUN-TOTING GOD WITH THE FACE OF APOLLO" is probably alien to him. APOLLO.
(I have decided to give Poseidon Sam's looks, and Zeus can look like John. Saying Bobby is Vulcan is not meant to be rude (at this point I'm surely mixing Greek and Roman-I dig that), but I like him that way--the question is--Mary is Athena, and Ellen is Hera? Jo is Persephone, Castiel is Mercury.)
And that's my random tangent for the day.