If i had to guess, i would say that most of their development time and money goes into their world building.
Tons of animations, models, routines etc etc.. an area in which they are completely unmatched, frankly, so the budget, time and experience shows up particularly.
The Art Director also said as much in the Gami Informer preview, and also stated that thats why they start building the map as an absolute priority.
I sincerely hope the game sells a shitload, nevermind the fact that im a fan of their games, but theyre one of the few teams who can and DOES invest a boat of cash into their games and it shows, making for some very unique experiences, whether you like them or not.
So id rather have more of this than another CoD, though of course.. to each their own!