Checkpoint only saves. Especially checkpoints in stealth games. The whole design reeks of "I know better than you." It is moderately more acceptable in platformers and completely unacceptable in open world games.
Also, terrible key-binding that was clearly not play-tested. I'm looking at you Shank.
Hell yeah, this is what really gets me annoyed too. There have been a few games that I didn't buy because of this.