So for quite some time now I've really been wanting Improved Vampiric Embrace back in my talent tree especially now that 2 of my most powerful dots tick faster, which works very well with VE. I've tried taking points out of several key talents, like Shadow Reach and Mind Blast, but I've come face to face with the realization that I may just need to drop Improved Spirit Tap. I know other Shadow Priests have done this, but I've always been afraid of taking the leap because of my irrational fear of running out of mana too early.
I'd like your opinions on the spec listed below, especially from those who don't have Improved Spirit tap. Do you find yourself running low on mana quicker? Are long fights a pain in the butt as far as mana goes?