So I decided to play the beginning of the game unpatched, because I was curious what needed polishing. It was mostly fine but there were many smaller graphical glitches, like shadows and alpha effects behaving weird. Also seemed to have slightly worse anti-aliasing.
There was one particular thing that looked horrible in the unpatched version: Kraven's mane. It looks significantly better in the patched version.
Anyway, after patching I began playing around with both Fidelity and Performance mode. I decided on Fidelity, because Performance shadows just aren't up to snuff IMO. I think most people wouldn't notice but I definitely did notice missing pedestrian shadows when you're above street level (maybe a bug?) and generally lower quality shadows. I say it might be a bug because shadows seem to only appear for pedestrians in the distance when looking at reflections... it's weird. I'm sure DF will look into it. In any case, Fidelity looks absolutely beautiful.
Lastly, about the actual gameplay: it's more Spider-Man. If you loved the previous games, there's no reason you won't love this one. It's gorgeous, it plays beautifully, and the story is interesting so far.
My only complaint right now is a petty but personal one: Brooklyn is too small. Obviously, I wasn't expecting the full borough, but it feels smaller than even GTAIV's Brooklyn, which is probably because traveling is so fast in this game. At least GTA's Broker had the elevated subway that goes all the way down to Coney Island. It's just weird seeing Coney without it. Edit: Actually, the subway tracks are there, but only half of it elevated. It's a weird change.