It is the main reasons. Priests are a very well-rounded class right now is due to the fact that they are easily the most offensive healer. By design, they are able to play both roles effectively, albeit with costs about WOW guide gold. Playing too offensively will be very detrimental and often costly to your mana pool. And figuring out the amount of time you can actually play offensively is a delicate process due due to being so susceptible to attacks; Shadow fiend rarely returns full mana when used about WOW guide gold.

There are rumors going around that Blizzard is considering alternatives to Priest mana regen other than Shadowfiend, when really giving fiend effective avoidance again is really all that is necessary to get WOW guide gold. Pushing it beyond this, which Blizzard might do, could yield a window of offensive play that is far too long due to Priest mana efficiency being too good. Right now, you are looking at like 2-3 minutes of heavy burns and dispels before you are in trouble with mana. With the fiend buff and other rumored changes (such as buffs to hymn of hope) that 2-3 minutes might increase to 4-5 about cheap WOW guide gold.

If Blizzard really has increasing Priest mana efficiency as a priority, they need to blend it within the Shadow tree.Shadow Priests have a couple of options right now (that is if you are actually crazy enough to want to play Shadow); 20/0/51 with points in Imp PW: S and Absolution, or picking up crit talents in shadow while forfeiting the extra survivability and mana efficiency. As of right now, there is little evidence pointing towards speccing for crit as the most beneficial and ideal Shadow setup to get WOW guide gold. Even with the talents, your crit rate is generally still abysmal, and getting raped by the mana cost of dispel cancels out any benefit as it is. In addition, Shadow Priest mana pool has not really improved since level 70. If anything, in full deadly, you might have 1-2k more mana than you did in full brutal. Speccing spirit is not effective either when you can just snag the spirit trinket from 10 man nax if you really want the extra regen, and you lose the increased damage in SW: P. This does not take into account any of the other issues with Shadow either.