Apologies for bumping such an old thread, but I'm just now in the process of playing through almost all the COD campaigns @ 4K, and as I'm nearing the end of BO2 I'm starting to get really nervous about BO3, based on this thread (I'm playing through the various sub-series in order).
So far I've done:
COD2 - fantastic, one of the definitive WW2 FPS
COD4 - utterly superb, many memorable levels
MW2 - decent, but as has been mentioned, too many Michael Bay moments
MW3 - also decent
BO - decent, some good levels, some duff ones. Notably harder because the weapons seem to kick a lot more (and I play with a Dualshock 4, and don't get the aim assist on PC)
BO2 - opposite to BO1; weapons have almost no kick at all! This is the first COD that has started to drag well before the end. Not sure why.
Overall, the two biggest things that bug me in general about the series (but perhaps more so with the Treyarch games) are:
1) Too many scripted cinematic sequences with QTEs. Moreover, they are QTEs that are sometimes eminently failable. There aren't many dumber things in videogames than cinematic sequences that you get to watch again...and again... because someone, somewhere, decided the player ought to have a modicum of input, even though that input isn't engaging or interesting in the slightest. Just play the damn movie, game, if that's what you want to do, then let me get back to the business of shooting people, please.
2) Too many sudden deaths from grenades and exploding cars.