Well it's pretty easy to look at Sacred Shield healing done during burst periods.
http://www.worldoflogs.com/reports/4...#tab-healspell
With a couple of PW:S thrown in that would easily be 30% healing done, negating an entire 30% of a healing cooldown. Overhealing is a little difficult to analyse but you can't just disregard the fact that you will have more overhealing.
Why complicate it? Ignore Avenger's Shield for simplicity (should be roughly the same number of procs regardless). 20% haste means a 1.25 second GCD.
If you're doing your rotation correctly it'll look like this when not under SW:
CS - J - X
CS - X - J
CS - X - X
Under SW:
J - CS - J - X
That results in:
Holy Avenger, 16 "extra" holy power gained, 120s cooldown, 0.13 recurring HP/sec.
Sanctified Wrath, 4 "extra" holy power gained, 180s cooldown, 0.02 recurring HP/sec.
These are with the standard holy power gained subtracted. Remember that we are only concerned with any additional HP that will be gained during the cooldown. That's also assuming that we use both cooldowns as soon as they are available which is never the case. I find myself usually getting off 3 Holy Avengers compared to 2 Avenging Wraths on an average fight.
Overall it's around ~5% less ShotR uptime when using SW over HA. The key points when making a decision will be how useful the healing increase is and whether or not you need the long period of 100% ShotR uptime that HA provides (Empress and Wind Lord are both fantastic fights as examples of this).
I will agree that SW is attractive on heavy magic damage fights. Lei Shi and heroic Protectors immediately spring to mind. HA is useless for survivability on the former and much less worthwhile on the latter as more than half of the damage that you take is magical.
This is only partially true. With SW (especially under Bloodlust) you're pushing back all of your other abilities even more. CS and J are our weakest hitting abilities. Theck recently reran his sims in matlab to account for higher vengeance and HA is ahead regardless of vengeance when you are aiming for 15% expertise. If you don't want to cap expertise then SW will likely pull ahead, though remember that once you reach 50% melee haste, additional haste is actually a DPS loss. This will impact the DPS of SW during Bloodlust (a period where you will normally want to pop Avenging Wrath).
You can find the results of those sims here: http://maintankadin.failsafedesign.c...718671#p718671