I'll be doing 2 war 2 paladins 1 priest, or 3 warriors 1 shaman 1 priest. I'm also debating for the horde side, 4 warriors 1 shaman.

I expect it will blow through 5 mans effectively. The only downside of this group is, it's not going to be able to finesse when it's a little bit on the low level side. So no real CC. The upside is, it's just going to be an AOE melee cleave.