I can't test it right now but I'm quite sure last time I tested foresight against lv 60 field mobs it was roughly 10% mitigation. I never said overall rampart would outweigh all the nerfs we'll get, but I feel that you're understating the usefulness of having another mitigation cd that works for magic damage. Considering the encounter designs we've seen, with huge infrequent damage spikes, we'll have a really good mitigation toolkit outside tank stance with rampart and raw intuition at 90s cd, vengeance and thrill at 120s cd, and holmgang at 180s cd.