Lord Knight, Paladin, High Priest, Professor, Whitesmith, Creator, Assassin Cross, TaeKwon Master and Super Novice with a Soul Link can all use Coma by a cheap weapon they could buy in the store.
Edge, Book of the Dead[2].
High Wizard, Sniper, Ninja, Gunslinger, Clown ang Gypsy cannot.
The Coma weapons are actually difficult to obtain in iRO/kRO, they weren't meant to be sold like potions. Since somehow they have though been let out like this, how about giving a class in serious need of it the ability to Coma?
Sometimes, spamming skills isn't cutting it to kill enemies on the spot before their strip runs out so maybe killing them with Coma might do the trick.
Also, tons of enemies use FCP and re-FCP themselves in the middle of a battle as soon as it runs out which make the chances for a HW to win thinner.
If however a HW can stall enough time to be able to then break the enemy's shield, then the chances are better for the High Wizards.
High Wizards weren't as geldaz mentioned, meant to only spam Stave Crasher.