Blood is slow since you cant pull a lot of mobs in most situations. It can be convenient for dailies in bad gear, I could only take 1-2 mobs as freshly dinged 90 for them. By now I just pull whatever I see and steamroll it as frost, though. No way blood would be able to keep up. Can take 8 mobs no problem as frost, and I've yet to run into a situation where I can pull more mobs than that for my quests.