Just finished it.
Hate to say it but it was a letdown, even go so far as to say it's the worst game out of the 3.
Spoilers ahead:
Seattle is just plain boring, there's nothing unique about it, your cookie cutter american city.
New Orleans in inFamous 2 was WAY better, unique city, unique charm, unique setting.
Your electricity powers combined with the flooded city parts was a nice gameplay additon. In Seattle there's none of that.
It lacks variety, you basically have 2 city parts, they don't differ too much. The only exception is that the city part that gets unlocked during the game has higher buildings.
With inFamous 2 you got much better pacing and variety(city, swamps, oldtown).
Not to mention enemy types, you basically fight the same people all the time.
Again inFamous 2 did a much better job, you fight those huge enemies(alongside regulars) and it was just much more epic.
Also the sidekicks were kind of useless, they only really come in handy during the last mission.
inFamous 2 let you do missions with Kuo and Nix way more frequently and the moral system was better implemented because of that.
The game also felt kind of short, I thought really, this is it? Yes it is. inFamous 2 had way, way more content. Even without the mission editor!
Of course, graphics are great but coming from inFamous 2 it's a clear step down. Being a launch title I don't think they could have delivered that anyway, so I'll give them that.