I can agree that PoH spam to keep da rolling was pretty mindless but shielding people has both a debuff and a small GCD each cast. The amount of absorbs we are putting out with PW:S spam if people wanna call it that is far less than previously with da.
Unlike PW:S, rolling PoH/DA also had a cast time and couldn't be used on the move. It also had group limitations unlike PW:S, and you actually had to be diligent about keeping the DA stack active.
As it stands, the only thing you need to do is watch a boss timer, and simply start rolling PW:S on the raid when the timer is sub 15s. There's no downside to PW:S spam - no group, range or movement restrictions, very little overhealing, high HPS - and quite frankly, there's very little thought to its usage.
At my gear level, I'm having no issues sustaining heavy usage of PW:S, and this is even without me having the LMG. The LMG just makes PW:S spam so much more viable.
I don't know how this happened, but Disc went from a rather complicated spec to play well, to one that's mind numbingly boring now. Simply spam Atonement and PW:S and you can safely ignore the nuances of the spec and still do exceedingly well.