I dont understand why should I PC party composed of a lvl 15 warlord, wizard, cleric and rogue should absolutely OWN a NPC party composed of a lvl 15 warlord, wizard, cleric and rogue.
Makes no sense to me. I do however that this is the way the game is designed, and that only a fraction of your ressources should be expended against an encounter of your own level, but truly it's riddick....
...Truly, how is a lvl 15 guy supposed to feel good compared other lvl 15 NPCs of say his paragon class (ex: Kensei PC in a Kensei NPC order) if he knows he has 3 times more powers than them and is simply not playing the same game...
A level 15 Cleric NPC has 120+Con HP, Channel Divinity, Healing word, the same starting stats and stat increases as a PC, a cleric at will, 2 encounter, 2 utility, and one daily power. He has 2 healing surges and can use a second wind. Plus, he adds +5 to all his defenses, attack rolls, and damage rolls.
A level 15 Cleric PC has 82+Con HP, plus cleric abilities, 2 at wills, 4 encounter, 4 utility, and 3 daily powers. He has 7+con mod surges, and 9 feats, plus a bunch of magic items to boost him in other ways.
That NPC *WILL* use his daily during the fight, and he will use his 2 encouter abilities as well. I don't see the PC's as being 3 times more powerful.