It's not that difficult to do more DPS as a survival hunter than with an Spriest. Espaccally since the latest build, where the Spriest Raid DPS got nerved again, in a way that our finally DPS increase could even go down to 0% compared to TBC.
Actually no one needs a shadowpriest in any raid it's just loosing a raidslot you'd better fill with a retardin SV hunter or Moonkin f.a.