Having your Domain Spell be a Healing spell in order to use the principle power of the class is a huge cost of opportunity.
Augment Healing, Extra Turning, Divine Metamagic and Sudden Metamagic spells can mimic this class feature. Sure a RSoP can take these feats as well...but you then have a character maximized for healing...a character that is trying to min/max the # of hp healed....which is fine. Technically under the "strict interpretation" of RSoP...a OA Shaman dedicated to Pelor would almost be better...as the OA Shaman gets 2 Domain Spells per day at some levels.
Now if you are going to ignore all Rigor and Logic and decide the power of the RSoP applies to all spells on the Healing Domain list...the best healer is still not a cleric with the class...but instead a Favoured Soul with the Temporary HP alternative class ability from PHB II and a 3 levels of the Knight of the Raven PrC class from Expedition to Castle Ravenloft.
The Knight of the Raven PrC is btw a class that gives you:
1) Full BAB
2) D8 HP
3) Near Full Spell Casting ( you lose out on 1 spell casting level @ 1st level)
4) Raven Companion...that has the Celestial template...HP = to half your total...and is able to distract opponents as a free action causing them to lose actions, AoO etc and is rather hard to kill.
5) Feats that enable you to ignore or remove Negative Levels + ability damage...class grants feats from Liber Mortis
6) Class Gives you the Sun Domain for Free @ 3rd Level
7) Class Gives you a power to hurt Undead similar to the 10th level ability of the RsoP.
The only downside is you lose 2, of Turning Caster Levels...as similar to a Paladin it does not give you Turn Undead to 3rd level.
Of course the Turning Rules being what they are this is not that big of a deal.
Me thinks a Melee Cleric, with Divine Might, Righteous Might, Divine Power, with Power Attack and 10 levels of a FULL BAB class is scarier than a cleric casting a Maximize/Empowered Cure Light Wounds spell from his Domain Slot for 17 HPs of healing once per day.
Augment Healing, Extra Turning, Divine Metamagic and Sudden Metamagic spells can mimic this class feature. Sure a RSoP can take these feats as well...but you then have a character maximized for healing...a character that is trying to min/max the # of hp healed....which is fine. Technically under the "strict interpretation" of RSoP...a OA Shaman dedicated to Pelor would almost be better...as the OA Shaman gets 2 Domain Spells per day at some levels.
Now if you are going to ignore all Rigor and Logic and decide the power of the RSoP applies to all spells on the Healing Domain list...the best healer is still not a cleric with the class...but instead a Favoured Soul with the Temporary HP alternative class ability from PHB II and a 3 levels of the Knight of the Raven PrC class from Expedition to Castle Ravenloft.
The Knight of the Raven PrC is btw a class that gives you:
1) Full BAB
2) D8 HP
3) Near Full Spell Casting ( you lose out on 1 spell casting level @ 1st level)
4) Raven Companion...that has the Celestial template...HP = to half your total...and is able to distract opponents as a free action causing them to lose actions, AoO etc and is rather hard to kill.
5) Feats that enable you to ignore or remove Negative Levels + ability damage...class grants feats from Liber Mortis
6) Class Gives you the Sun Domain for Free @ 3rd Level
7) Class Gives you a power to hurt Undead similar to the 10th level ability of the RsoP.
The only downside is you lose 2, of Turning Caster Levels...as similar to a Paladin it does not give you Turn Undead to 3rd level.
Of course the Turning Rules being what they are this is not that big of a deal.
Me thinks a Melee Cleric, with Divine Might, Righteous Might, Divine Power, with Power Attack and 10 levels of a FULL BAB class is scarier than a cleric casting a Maximize/Empowered Cure Light Wounds spell from his Domain Slot for 17 HPs of healing once per day.