I finally got around to seeing this, and I have to say that, aside from Iron Man, this is almost certainly my favorite Marvel adaptation.
Ray Stevenson really nails Frank Castle (but I think he's pretty damn awesome, anyway) and the story could have been lifted right from a comic book. The violence is very graphic, but in a few scenes, it is so completely over the top that it harkens back to the character's comic book roots.
It's a shame this movie didn't get a good release date and tanked as the box office. I think Lexi Alexander did a bang up job, and if you're a fan of the character, this is The Punisher done right.