Yeah. I just saw it. I told you :p umm...I know a few routes in certain places that saves time but nothing major that I can think of off the top of my head. Ill watch a run and take notes.
May have found one at the long fight after you get the grenade launcher. It avoids the trigger to spawn the enemies as well as the trigger to play the scene for the turret. Don't have to slide down the rope either.