Caught a showing tonight and I've gotta say, it's easily my favorite Marvel movie to date, and it's got a shot for taking the top spot for comics movies in general for me, though I'd need to watch it a few more times to really say that. Part of that's because I'm a big Cap fan to begin with and the Winter Soldier is one of my favorite arcs/characters, but it's also because everything from the action to the story to the acting was just perfect for me.
The best part for me was how they finally gave us Cap fighting and using his shield like he does in the comics with some crazy rebounds, and fully using his super strength and conditioning. The only thing that trumped it was THEN making the Winter Soldier a huge badass and giant threat by having him repeatedly go toe-to-toe with Cap. The Cap fanboy in me cheered like mad during that.
End Credits Observation: Using Von Strucker in connection to the twins is actually pretty interesting not just because it introduces them to us, but because he can actually take Magneto's place as their father. He is, after all, the father of twin mutants (Fenris, aka Andrea and Andreas Von Strucker) as well who might very well be tied up over at Fox Studios along with the X-Men due to them being mutants and former X-Men villains. If so, it's a pretty clever workaround on Marvel's part and one I approve of.
I do like the fact that he also seems like more than just a throwaway cameo villain in AoU as many feared he might just be, and with his ties to AIM it's possible he might have more to do with Ultron than many people believed. It's obvious they're not going the comics route with Ultron, and it's been repeatedly hinted it would tie back to Stark-tech. AIM's certainly stolen their fair share of Stark tech in the comics: I could see Ultron turning out to be an AIM experiment with the JARVIS AI gone horribly rogue.