I prefer haste over mastery. Can't link ATM because I'm posting from phone but I'm typically ranked top 10 world for most fights in 10 heroic. Hogar - gag reflex dark iron
Honestly, I sim them. Simulationcraft is so easy to use right now that everyone who is in doubt of what stats to choose should simply run it a few times to come up with valid priorities.
At my current gear lvl (490), I'm going Haste > Mastery, but the value of extra Haste is declining rapidly for me.
If only there was a better option 1 coin per week since week 1 of heroics + regular loot table and I haven't seen it once . One time lfr was kind enough to tell me that I would have gotten it if I wasn't previously saved.
Yeah its close on MR. Robot but it suggests haste, I currently have the 4set as you see 496 ilvl, but I do have a few better pieces like the chestpiece that is bis and a different belt that shows bis, and a set of 503 legs that look better, but when I sim it shows the 4piece as being better... I don't know how much weight mr robot gives the 4set bonus