Started playing the campaign on Legendary alone yesterday. Insanely hard, I was more kinda preparing for playing some co-op Legendary later on, but its actually a lot of fun trying to do it on your own without the respawns. The AI is just so brutal and clever at flanking that you really need to keep on your toes, and while you'll be able to take a few steps back and pick guys off from a distance in some situations, then there are others where you just need to engage it like a puzzle from each checkpoint, and plan carefully how to get each enemy. Also the enemies you didn't even notice on Normal or Heroic suddenly become an actual obstacle here.
Really having an awesome time with it on Legendary, great stuff for when you've completed the game. Takes me about 3x the time it took on my first play through ![]()