If you played the alpha/beta (alpha exemplified a little more) you would have noticed the titans being slightly tougher to kill. That is why. Speed affects jump height and stuff, which isn't really noticeable (it is there). Recoverability and Toughness would make for the best gaurdian in both PvE and PVP No, it only affects after it starts to heal. The speed advantage in healing could save your life, though