Just watched this on Netflix. I thought it was ok and it is for a more mature audience. I don't know that I would go out and buy this but to watch it on Netflix was fine. Marvel put a ton of stuff on Netflix for streaming including Spider Woman, the Hulk animated show, FF and some more Spiderman also a Black Panther series. I'm sure I missed some.
As far as the Iron Man Extremis [spoiler]It is only 6 episodes and all of them are under 20 min. I was surprised how much blood was in it. A little too much for an animated show I thought. This was also not done in a normal way. Check it out to see what I mean.[/spoiler]
It's a motion comic. They took a comic series that ran in print and lightly animated it. There is even one for Buffy Season 8 on DVD.