Mana efficiency isn't a problem. No one is complaining about going oom and all of our players actually use mana pots, flask, food, etc. Will the 10% less healing cause the other healers to flounder? Not likely. And if the main selling point of a paladin healer is spamming 2k heals and the occassional holy light because "they can for longer", it's lost on the fact that we're killing shit so fast it doesn't matter and would kill even faster with another dps. On reaver, our spriest was healing nearly as much. That's how irrelevant that heal spam is for us.
The blessings I get. And part of the issue may be that our other healers are just amazing. But as for the class itself, I think everyone has answered my question; holy paladins kinda suck. And since he's even parsing blue, with that low hps, the 'best' healing I can expect isn't going to be much better or more necessary.
Anyone saying hps doesn't matter just sounds like someone who consistently parses poorly, tbh. It is THE metric that most defines how much your raid actually needs their healing.