Throughput is lower for resto shaman than any other healer. Longevity is also lower except compared to Priests I would say, unless you're feeding the shaman mana with a pet or something. Burst healing is lower and pretty much ALL healing except dispel healing is dependant upon casting, opening us up to interrupts. Out of all the healers we have the least throughput with instant casts.On topic though, a huge reason Resto is a top healer is because of their incredible mana longevity and throughput. Most of the buffs recently were purely PvE reasons though, which is what makes it even more evident that they're strong (they can't seem to buff PvE without somehow overbuffing it, I don't understand it that much).
I guess I just disagree completely with that entire paragraph.
The shaman's strength is not his heals. It's Wind Shear and totems.