Bah... COD is a buggy POS. It's extremely over-rated as well, as far as graphics go.
It's not all that realistic. It's got excessive sun glare and shadows, that's what attracts the eye and makes it stand out. Other than that, it's not all that good. The textures are so-so, and not very realistic (bare metal showing excessively from paint chipping on a BOB era 110? Hell no!) The view distance is limited by a rather short and obvious fogging plane. The land textures aren't very good either, and are the typical bland flat featureless IL2 terrains as well. Also, they add false details arbitrarily just to make you see something, and you think "wow, that's so detailed" regardless of whether it's realistic.
For example: I'm not so sure you can see whitecaps on the ocean that size from 15k+ altitude.
AH has better graphics in several areas than COD does. Sure it could use some improvement, but from what I read of COD, it'll fail to intall, let alone run, let alone play smoothly, 80% of the time. At least AH works.