Originally Posted by
Selesnya
PWS is awful for its mana cost. Keeping it on Rapture cooldown is great, but I wouldn't touch it as an actual healing spell while Rapture is on cooldown. It's an emergency/preparation "cooldown", totally situational and barely belonging into a normal healing rotation. You mostly save people with it.
Your mana regeneration is somewhere around ~3000/sec with shadowfiend and trinket on cooldown, with solace it's maybe ~4000/sec. I'm not sure how anyone is going to spend ~10000 mana/sec for more than 20 seconds. While the LMG proc is up? Maybe. But that is assuming that the targets you are going to shield aren't debuffed and are going to take damage predictably within the next 15 seconds, conditions which I find doubtful.
12k spirit won't allow you to PWS spam either. Neither will 20k spirit. 9k is a good guideline right now, 11000 spirit on top of that would be another ~1200mana/sec, or 5200/sec with the example above. That still doesn't get you anywhere near to PWS spam either. Not to mention that you just dumped 11000 of throughput stats into pure mana regeneration.
If Discs appear on healing meters with 150k+ it's because of SS and PoH, certainly not because of a single target shield.
Havoc12 explained it quite well. Disc is not about PWS.