The best part of Assize isn't the 300 AoE dmg potency or the instant medica.

It's the 10% MP regen which based off of your PIE, making that stat even better to have more of now. Before 3.0 many would say you would stack as comfortably as you could. Now the more PIE you get, the more you'll be restoring. In a 13 minute fight in savage with about 13k MP you'll get it off about 8 times, which can be over 10k MP restored. Nevermind I didn't even mention Shroud, or natural 2% PIE regen as well. Big boy MP regen to say the least, helping burst DPS and healing progression. It should be used strategically, almost always on-cooldown to get the most from it.