I've played a custom resurrect priest for few hours around R15. Onyx bishop is insane card, if you can manipulate graveyard to contain good quality minions.
I played vs hunter. Priest of the Feast was my first minion, only used spells before that. He killed the priest, I played onyx bishop -> resurrected PotF. Turn 6 I play my 2nd bishop, PotF #2. The 1st bishop gets frost trapped and I play it at 7 mana. It was so good he had to use "summon all companions" to clear the board (didn't manage to clear it).
Real problem is turns 1 - 4, I have to somehow survive those turns without being in a losing position WHILE having not played any trash minions. Turn #3 injured blademasters are fine, but I'd like to include some 1- and 2-mana minions. But priest doesn't have any good ones except Northshire Cleric. I can use the 0-mana summoning spell to fill those slots, but in one game I got the Jewelled Scarab from it and resurrected that 1/1 twice during that game.
But resurrecting NC (combined with circle of healing) made me draw like 10 cards more than my opponent.