This superior sequel proves that golden rule that all other films should follow: the "more, more, more" impulse of the Suits--double the thrills, double your money--is wrong, and always leads to disaster. (And will, next movie.) But all you really need is a great story with a great antagonist.
Spider-Man was great, but this film is blasting on all cylinders with confidence. Singer had just raised the bar with the excellent X-Men 2. Raimi follows the same wise course, knowing that to go wider you should also go deeper. Like Bruce Wayne, Peter's is a life borne out of tragedy. But it is their facing of this that defines them. The '90s Batman films failed to convey this core to the character, so they became style vortexes with a hollow heart that devoured themselves. Raimi makes up for the mistake by anchoring the story out of the character's hearts. Peter and Mary Jane lose their equilibrium without each other. Octavius loses his grip with the loss of his soul mate. Harry is slowly losing his mind after the death in his family. Even when each person makes tragic choices, we feel empathy for why. It's the interior that gives all the exterior meaning and impact.
Again, the studio had planned multiple villains, but again Raimi reduced it to one. The skillful focus on the tragedy of Doc Ock takes such riveting precedence, that even setting the infrastructure of future villains (The Lizard, Man-Wolf, Goblin II) is deftly underplayed and unobtrusive. Raimi is setting another golden rule to follow: background infrastructure is basic worldbuilding, but franchise-building that overruns the story is a mistake.
This film owes its storytelling power to the classic '60s comics, and specifically to "Spider-Man No More!" (#50, July 1967) by Stan Lee and John Romita, Sr. That's Lee's angst and absurdism in their mouths, that's Romita's powerhouse punches tearing up the bricks, that's Steve Ditko's body shapes in all Spidey's swinging. The film knows where to take him because it knows where he comes from.