Nice guide, it's helped a lot so far, especially on Pegasus Day.
At the moment though I'm stuck on Dam at the room overlooking the turbines. I load my checkpoint, kill about 20-30 enemies and still can't reach a checkpoint. I know i need more than 50% health to get a checkpoint but at one stage i made it down the elevator, down another floor, through the long corridor with the sniping guy behind a crate and then up a staircase all with FULL health and died with no checkpoint. I've been at this point longer than it took to get to this mission. Anybody know if I'm doing something wrong or if there's an easier way?