Fluid Death, Tia's Grace, as well as both raiding trinkets have been proven to be better, even with the mastery bonus. The biggest problem with it is that it goes off of spell hit (17%) so it can miss, and even though it has no ICD it doesn't proc all that much. I thought it was going to be better than my Tia's Grace myself until people got to testing it and it just doesn't live up to what it should be...at least I was able to get my money back as I didn't equip it.