The actor they cast as John was a great physical match-- those eyes!-- but WTF was up with that accent? He had that pseudo-Brooklyn rising inflection on the end of his sentences like the Aussies actors use in "Without A Trace," and it's wrong and unnecessary. JDM uses a little bit of a drawl for his character, and the YoungJohn actor's from Florida. It really irked me.
A lot of people liked Dean steering John toward the Impala, but since John was a mechanic son of a family of mechanics (fanon becomes canon?) he should have recognized its value on his own.
I also found YoungMary kind of dippy at first, and the kick-boxing scene in the alley with Dean... not the fighting style I expect a Midwestern anybody to know in that era, especially a girl.
The idea of her being a hunter really bugged me at first. Maybe it was the feeling of being Jossed, or as if Kripke was trying to resurrect Jo once again (the actress looks a lot like her). I don't know. The idea that Sam and Dean would be named after her parents, and no-one would have mentioned that earlier to the boys seemed really 'off' to me.
But then Mitch Pileggi started to win me over, with his hardass "Just Like John Winchester" behavior (oh, the irony). By the time we got to the last part of the episode, I could not contain myself. Oh, Mitch-- finally you get a chance to work it. The YED is a fun, fun part to play. :D
The tonsil-hockey with Mary at the end... yick. That seemed wrong and unnecessary, somehow. Did the demon go that route with the farmboy too? And did the farmboy's deal involve killing his father, because the father beat up the mother? Where would it have gone for the woman the demon was visiting? Or would she have bargained for her husband's life? Seems like the YED might be cutting into the Crossroads Demons' action a little bit.
Now, one of the things I loved about this episode were the ways in which Destiny is Destiny is Destiny. The things you try to prevent will happen all the same-- Mary will be compelled to make her choice for reasons you can't foresee, and once you discover why she makes it... you'd have to let her.
In many ways, this is like the question of Sam turning toward a path of darkness. Dean and Sam both worried about this in Season Two, and the demon took Sam and tried to make him fight to lead the demon army. In the end, Sam was killed, and the demon's plan didn't work. But because Dean brought Sam back from death, and paid his own life over as the price, Dean's own death made Sam turn in despair and frustration toward the powers the demon had given him.
I.e., Sam is heading toward that same dark future, even if he's arriving there sideways.
I do find it strange that Castiel told Dean he was being sent back to prevent something from happening ("You have to stop it"), and in fact already knew that Dean could only witness but not change what happened. It constitutes lying, and that doesn't fit with anything we've heard about angels. Or to summarize... it's careless writing.
I'll spare you the obviousness of Sam running off in a car with Ruby 2.0 for the episode and how that must work in really well with Jared's filming schedule. :( I don't like that, actually-- the boys' primary jobs are working on Supernatural, and they ought to expect to be present for filming all the episodes. I know, I know-- their agents probably work this out with the SPN producers. Nonetheless, it's the principle of the thing!
Back to your regularly scheduled "Dean cries so pretty" and "Mitch had too many clothes on" and "Castiel is hot in an aloof kind of way" discussions. ;)