The cert stuns works against bosses (wrong description). Also people choosing to have crit dmg reduction over having key stats at 100% is a common error, lets say you are a healer with 93% cast and you choose a crit dmg reduction over 10% cast cert because 103% is overcap, while in fact that 7% cast would give you more bulk. Crit or m-crit should always be at 100% counting pod/events/consumables, unless you are a debuffer, atkspd at 60-70% for physicals, and cast at 100% for healers and m-dps that have cast on their highest dps skills.