Well single player is far superior to the bad company 2 offerings. Not quite up there with recent call of dutys mostly because of those last minute polish things. I enjoyed the story, the game suffers because it has less iconic characters and fewer memorable set pieces but it's well presented if you ask me. The guns feel great, not just a few of them. Swapping out with any of the dropped weapons and they just felt powerful and accurate. The pacing works well, close quarters and ranged, sniping, vehicles and some different locations. Health balance seems alright, enemies go down super quick but you can take a few bullets in rapid succession. As long as you keep behind some cover it's not hard.
Didn't really face much infinite respawning stuff. Single player doesn't rely on destruction like BC2 did so often, perhaps they went too far in the opposite direction though. Doesn't have stupid segments like when you had to run from house to house to keep warm. Seems Danger Close helped on this one and I think it shows. QTE things are just cutscenes that require button presses, it's not like you have to push them fast, just make sure you get them right. I wouldn't call the single player great, but it was good enough to warrant a play through. Took about 4-5hrs for me.