Back in tier 15 our hunter coined every weapon boss for 9 weeks and managed to get everything off their loot except for the weapon table multiple times.
It took me 22 kills of Heroic Megaera to get my heroic trinket.
Now this tier its looking like I will get the same rng as i've coined Dark Shamans 7 times, gotten 2 necks - 1 hwf, 2 belts - 1 hwf and shoulders.
Rng is rng, still though its better than not having coins and being forced to wait for it to drop, then get out rolled or have it not given to you.