COD 2 is crazy hard compared to MW2. I am pretty sure you can't sprint in COD2 or throw grenades back.
It is a great campaign though that is very tough. There were about 4 or 5 levels that were frustrating but I would say just as hard as COD WAR (I am almost to the last 3 levels on this..I know the last 2 are brutal).
MW2 was a cake walk on Veteran. Seriously