Ive been lookin around a little, and I've noticed all the high-end guilds' SPriests using the 4set.. my only question with this is: Don't you already spit out Mind Flays fast enough as is?!
Im just wondering if it would be more of an overall DPS increase to use the 4set (for the hastened MF's) or to just get more haste/crit for your DoT's?..