I played Killzone:SF quite a bit, in fact this is the only Killzone that I ever completed!
Now, I liked the sound, the graphics, the guns, and MOST of the levels (about 2/3)... then there were some boring sections, especially the flying/falling/zero gravity sections where the controls were just plain bad, I put that on a rushed release to meed the console release date :-/
But comparing the campaign to CoD or even Battlefield is strange at best, the levels had many objectives that you can approach in different ways and often in a different order, this is something I really appreciated! and there are no stupid allies to play the game in your place, you actually need to win these battles!
On the down side, a few of the levels are linear, which is not always bad, the bad sections are the battles where control is messed up (the flying sections, or sections where you have to control a turret to hold ground from attacking ennemies).... the story is bad, the characters not very interesting and the end only makes it even less meaningful, I wish all games had stories like Uncharted, TLoU, God of War or even Metal Gear.
