both are good healer's and play their role in the raid, as a SCH you really shouldn't be to worried about healing like a WHM does its not your area.
I can tell you for sure SCH is by far the better single target healer and this is what they were designed to be, they keep the tank topped and support the WHM's raid healing by shielding the raid! WHM is the king of raid healing and benefit from the having a good SCH that can focus tank while the WHM keeps the raid up with spot and AOE healing.
there is no better we both have our role and if everyone in a party plays their role correctly and dodges mechanic's that should be avoided aswell as interrupt, pick up adds, and dps down mobs that can wipe a raid there should be no issue healing any 4 man dungeon (including pharos) and especially any other raid.
