I used to try various approach at some points, or just making fun with the environment and enemies together, or making a neccesary progress if some part on Delta difficulty was too hard for me, without being affraid of going billions of miles again and again and be frustrated again and again!!
Checkpoints are far away, so observation + making any tactics = be more frustrated when killed. The more time you spend per checkpoint the more you are frustrated when killed. At least thank you, that I don't have to look for dog tags, souveniers,... again and again.... It's funny that the game suggest observing before going to action.
Is it so difficult to add two keyboard keys for manual Save and Load and keep also checkpoints, as it was in Crysis 1 ??
Ooooh, I forgot, Crysis 2 is a CONSOLE game ported to PC and consoles don't have enough keys :XX Shame on you Crytek !
BTW: Load menu shows only name and time ??? What about picture of the saved position like in Crysis 1?? ... Ohhh, it would hurt performance of consoles, or they don't even support it

Where is your PC devotion Crytek?