The skill Mercilful Intervention has a 80 second cooldown by default. and is a Meditation. When you equip the faster cooldown trait, it keeps the 80second cooldown, rather than dropping it to 64 seconds.
I noticed this when trying to do stuff in Orr with my friend. Its not game breaking at the moment, but is making my build more challenging to use.
:) I hope ANet fixes this ASAP.
Best of luck
-Damen