Post by Aylia
one more point in imp pw:s taken out of shadow focus since at 70 resisting wont be as much of a problem with rune of perfection
Er, not quite. The Rune of Perfection
has spell penetration on it, which is something entirely different from spell hit.
Spell penetration lowers your target's resistance to the spells you cast. It only works on targets that have resistances in the first place (through buffs, gear, etc), and it can't lower resistances below 0. This is essentially useless in PvE, and only useful in PvP if your targets actually have any resistance on them.
Spell hit increases your chance to hit with spells--the more spell hit you have, the less of a chance there is that a target will resist your spells. In order to get a 99% hit rating (which is the highest amount you can get, or the "hit cap"), you need to have 16% spell hit at level 70. You should definitely make sure that you're at the hit cap, since it's one of the best ways to maximize your DPS.
You get 10% spell hit with 5/5 Shadow Focus. That means you only need to make up 6% through gear. The only reason that you'll generally see shadow priests taking points out of Shadow Focus is because they have more than 6% hit on their gear, and thus don't have to make the whole 10% up through talents.