There's been a lot of consternation about this film on line. It seems people are very upset about it.
Now, I hardly find these Marc Webb/Andrew Garfield-led Spider-Man films to be without flaw, you can find my review of the original film here. That being said, my initial reaction upon leaving the theatre after seeing The Amazing Spider-Man 2 was that it was my personal favorite of all the Spider-Man films that have been made.
Strong words? Possibly, and perhaps repeat viewing may change my mind. However, this film FELT like the Spider-Man I have enjoyed in the comics, and the changes made from the comic all made sense and felt OK, to me.

Richard Parker's research, and therefore, Peter Parker directly? No, not really, but it also wasn't such an egregious breach of storytelling that it made me upset. As I have always said about "cannon" and "retcons," if they open storytelling doors, I am fundamentally in favor of them.
And, here's the deal, I am interested in what they will do with this Sinister Six movie, and what will happen with the team that Harry Osborne is building. Do I think it's the best idea in the world? A film (apparently) totally about villains? Maybe not, but I'm willing to concede that it could result in an interesting film. Also that where The Amazing Spider-Man 2 leaves that storyline makes me more interested.
OK, so why did I love this film so much? Because for a specific reason that a lot of people have chosen to criticize it. This being Gwen Stacy's death and how Peter, and the film chooses to deal with it. I've heard a lot of criticism that the film "let's Peter off the hook" for Gwen's death.
Well, yes, but I'd argue that's the whole point.
See, as opposed to the Sam Raimi-directed Spider-Man trilogy, Webb and his team have embraced "with great power comes great responsibility." Whereas Raimi (with star Toby Maguire) presented a Peter Parker who was CONSTANTLY wallowing in, and almost solely motivated by guilt, Webb and Garfield have crafted a Parker that, even in the face of his greatest losses, embraces a responsibility to something other than himself and his martyr complex. The film is about moving past fear and pain.
When Peter returns to the suit and faces down The Rhino in the closing minutes, it is a statement about heroism that Raimi simply never made. The added bonus of the small child who tries to be the replacement for the missing Spider-Man only reinforces the point. Spider-Man is a hero because he does what he can, what only he can to do, because it is right. That sacrifices will be made, and forced on him, but that is HIS choice. Just as it was Gwen's choice to put herself in harm's way. And those sacrifices, they're part of living life to the fullest. Standing by a doing nothing? Not trying? THAT is true failure.
On top of all that, even in the comics, Gwen's death was NEVER Peter's fault. He may have failed to save her, but The Green Goblin killed her, period.
Not to mention that this film, more than any other Spider-Man film, FEELS like Spider-Man. The character is spot-on. The situations are solid superhero fare (is the Electro storyline somewhat reminiscent of The Riddler in Batman Forever? Sure. There are no new stories). The direction is flat-out stunning, and the action set pieces are pure, unfiltered Spider-Man.
It's just a fucking fun movie to watch, and it got me truly emotional at least twice. You really can't expect much more than that.
So, yes, I really enjoyed The Amazing Spider-Man 2. I'm sure I'll take heat for that opinion among my friends whom I think were more interested in stoking a personal rage over a Alex Kurtzman and Robert Orci scripted film than anything else. For me, it's about how I felt watching the film, and this certainly did not have the third-act trainwreck of Star Trek Into Darkness, for example.
I'm recommending it. I had a great time.