I guess, yeah. With Contracts being the middle ground.
Contracts is the only game to date in the series that seemed to have the AI really planned for every setting in the game. Just playing the first level forces you to play a different way between Normal and Professional playthroughs, and I'm simply talking about walking and getting out of the asylum. Blood Money was full of goons that seemed really eager to not fight you, and Silent Assassin was loaded with guards who were keen and ready to shoot at you. Granted, both types really seemed to compliment the settings they had. I think a cop in Vegas would be less keen on blowing a hole in someones skull when compared to a group of Afghan soldiers guarding a nuclear bomb.