Reckoning is working even better than it was vanilla. If you just try to get it to work like normal all it will do is reset your swing timer. You have to make a macro with /startattack /stopattack, then just spam it between swings. As soon as you are crit you immediately retaliate with 2 swings. I melt prebis warriors that crit me. Legit camped a prebis 60 fury warrior when i was level 49 because he just fed me crits and got destroyed.
Reckbomb sit stacking also still works but requires a little finesse. You have to sit, then stand the exact moment the mob attacks you, and you get the stack. Once you get the rythm down you can get reck stacks pretty reliably.