Infinity Ward are not great developers. While they make a mean shooter, their games are nowhere near the caliber or stories of Half-Life, Deus Ex, System Shock or Bioshock.
i don't know what to think of IW tbh. I do think, however, that the likes of CoD4, 5 and 6 are better than the afforementioned games' online playability imo. This makes them a better game for me, mainly because i can't stand a FPS trying to take on the role of an RPG as well, i just wanna get on it and shoot things, not have to sit through minutes and hours of cinematics, i'd only expect that from the likes of FF etc.