Are you serious? A cutting edge progression guild will take a 20% damage buff to a strong DPS, if they can!

And yes I certainly _can_ compare to WoW, because situations are exactly comparable. Both games have cutting edge content where healing is made challenging by burst damage, mana pressure, overhealing concerns, and movement. SCH is far better under mana pressure than WHM, SCH handles overhealing far better because shields never overheal, SCH blunts big spikes of damage using their damage reduction abilities (virus/sacred soil) and shields, and SCH heals far more during movement phases due to their fairy. Healing meters show SCH outheal WHM by a significant amount (10-20% usually). SCH need a weakness, and their weakness is poor stacking and poor AoE burst. Removing their weaknesses will make them into a healing superman.
HoT is prone to sniping given the long GCD and mana constraint WHM has at the current gear lvl restricing HoT rolling, 2 WHMs waiting for both HoT tick wont have the so called out healing.Besides healing is not dpsing, you can only heal so much until your target is at full HP, citing on HPS is a sign of bad healer actually. You need way more info to determine a healer's usefulness, like how it tops off people after a big spike in raid damage, smooths dmg spike on tanks and raid, etc, which requires the person who is judging to know both healers and the nature of the fight.

Take WoW for example: disc priest is at the bottom of the chart for a very long time until Bliz decided to count shield number in combat log. And unlike here, disc priest shield is a game breaker in some particular encounters. HPS aint anything.

I seriously think that you should level a SCH to 50 to actually feel there is something not working right with the class. It has potential, true .... but on paper. After all if you are dedicated for healing you should level both classes. Its not even time consuming, a week with moderate time allotment should be more than enough.