7/10
Theo wanted to watch this so I chose the slightly re-worked "Editor's Cut" from the Blu-Ray bonus disc in the 4K box. This was only the second time I've seen this film, and I liked it more than most people back when it opened in 2007 -- https://www.andyfilm.com/5-15-07.html
On the whole, I still found SPIDER-MAN 3 to be more interesting than most super-hero films -- yet it's easy to see why the sequel failed to measure up to Sam Raimi's two predecessors:
-The general downbeat tone of the entire movie. This might be the saddest super-hero movie ever: Peter Parker fumbles his relationship with MJ, whose career takes a nosedive after she's fired from her big Broadway show. Later he gets infected with the Venom symbiote which turns him into an emo-jerk. Meanwhile the Sandman is a "wrong place wrong time" criminal responsible for Uncle Ben's death, trying to do good for his ailing little daughter; villain Venom is an obnoxious photographer whom Parker humiliates; and Harry Osborn, still wanting revenge for Spidey's involvement in his father's death, ruins Peter and MJ's relationship before a late-game change of heart.
I mean, Peter Parker CRIES repeatedly in this film -- and it's amazing how "down" the entire mood of this movie is. The line running through nearly every element of the plot is a downer. There are scant moments of Spider-Man triumphing over the bad guys, few fun set-pieces -- and yet, ironically, the fans who disliked this movie hated all the scenes where "Emo Pete" struts his stuff on the streets of NYC. They miss the fact those sequences are vitally needed as the only (silly) thing off-setting the gloomy, morose mood of the entire film. Those scenes showcase Raimi's sense of humor, which can do little to brighten the heavy mood the rest of the picture generates.
-A tighter, more focused screenplay. Clearly this one needed another rewrite, as there's both too many villains, and not enough development of most story elements at the same time. How can you make a movie with Venom and relegate the actual creature to the last 20 minutes of the picture? And why is Gwen Stacey even in this film? Alvin Sargent is listed as having performed a draft on the movie, but more work was clearly needed as Sam and Ivan Raimi's script just isn't as air-tight as the previous two pictures in both structure and content.
Still lots of positive things in the movie -- good performances (even if I remember audiences laughing outloud at Toby Maguire crying at least once), an exciting climax, and a Christopher Young score a little richer than the typical Elfman fare (there's also more of it, apparently, in this editor's cut, though I have no idea what was changed). When you compare it to the bland generic nature of most Marvel movies, 3 is still a superior package of entertainment, even with its problems.
It's also a shame they canceled SPIDER-MAN 4 and didn't allow this group to conclude the series on a more positive, upbeat note -- in hindsight (and considering where Sony went with the Andrew Garfield films), that was more of a mistake than SPIDER-MAN 3.
Compare to the Disney Spidey films, which are technically...fine, but have zero personality from the "auteur" behind Clown and Cop Car. 
They're very likable movies, with a likeable lead, but they're the perfect example of how much personality we've lost in the last 20 years when it comes to franchise filmmaking. Thirty years ago, we had Tim Burton slathering his gothic perversity all over Batman Returns (one of the best Batman films of all). Eighteen years ago, we had Raimi throwing this terrifying, Evil Dead sh!t into his second Spidey movie...