Yes, but using Holy Shock is itself a reduction to HPS unless you're moving and the 4pc bonus is not enough to compensate for it. On heroic Hodir there's a lot of movement, but Val'kyrs?

This bonus is not about improving our HPS, though. It's about reducing the drawback Holy Paladins suffer when we have to move.

Except that the HoT portion of T9 was the one of the main reasons FoL users were sticking with SP builds.

Movement in heroic Val'kyrs in our strat (similar to paragon's first released video of hardmode) is either very high (ball catching) or non-existent (melee range).
In the case that you are ball catching this is a huge buff as you'll be constantly moving to grab/avoid balls. (we actually only have druid/priest healers doing this).
In the case that you are in melee range you'll get an autoattack whenever you use HS, which on average, refunds the cost of the HS, causing it to be a massive increase in HPM. (I stay in melee for SoW and uninterrupted healing...)

HS has 3 primary purposes:
(1) Landing a heal in time to save someone that won't survive 1.X seconds.
(2) Landing a heal while having to move or avoiding an interrupt effect.
(3) High mana efficiency while being in melee range of a boss.

In a fight that has an anti-melee gimmick and minimal movement/no interrupts, HS is only really useful for (1), and in that case the set bonus will have diminished value. If you think critically about this situation you'll realize that there are only a few fights in t8/t9 (thorim, vezax, beasts).

Tier 10 Holy Relic: Your Holy Shock spell grants 85 spell power for 15 sec. Stacks up to 3 times.

I like it better than the T9 relic (that didn't have a 100% proc chance like this one), however I fear that the item level 200 one will still be better.

Yes, so this will be the 4th Tier of Relic that's frankly bad in comparison to the Heroic Badge one. Perhaps we should all start raving about it and promising to use it just in case (god forbid) they nerf Renewal as an incentive to upgrade. It is a little odd to be honest, the Tier 10 libram will help me heal heroics, and the heroic libram helps me heal hard modes. Who can fathom the thinking at work.

On another note, has anyone else noticed a giant increase in Flashbots lately? Having to explain to what seems like every new trial why Flash of Light is not really a suitable spell for healing Heroic Gormok (and before that HM Thorim and before that Sarth+3) is actually quite depressing.

I agree with the t10 libram comments, and even think that it just complicates things even further especially for people who are reluctant to use HS, but use their haste-heavy HLs to cover the gap. Yet another stack and countdown to watch while trying to keep up with the healing. Someone's eyes will bleed. For HL build, imo the heroic libram is still unbeatable. Anything that doesn't give mp5 stacks or haste stacks won't beat the heroic libram imo. With FoL builds, there's the state of art PvP librams with nice boost to FoL, which will also keep dominating arenas (my opinion against the comment that t10 libram can be good in arena). Another reason for me to believe that it'll be quite weak is because, with the new tier of items, I normally expect to see higher stats than today. So the benefit from being able to cast an additional HL thanks to the mana reduction of heroic emblem libram scales with every new tier set as the stats increase and HL mana cost stays the same whereas the additional SP from t10 libram will see a diminishing effectiveness as paladins continue gearing up.

As for the increase in FoL oriented players: I see nothing wrong with them in terms of healing hardmodes, given that you have a solid raid healing squad. The very nice thing about FoL is the sustainable and predictable stream of healing on your tank(s). Assuming thre will be more 2-3 tank encounters in the game, your flashbot, as you'd like to call them, will ensure a quite stable 6-7.5k HPS (to be increased with new tier content) without much fluctuations due to DP or high difference between hit/crit as in the difference with HL hit/crit. The very questionable thing is whether your trials have the gear for the high SP/mp5 requirements of the build imo.

Nothing wrong with 'flashbots' per se... it depends on your healing composition in raids.
If you have Multiple holy paladins, then there's an advantage to having one of them use a diffrent healing strategy.

It's the same reason why you don't want to take ONLY holy paladins to heal your raid, even if they have the highest total throughput (even if you have a SPriest to cover PWF, elemental shammy to cover totems and balance druids to cover druid buffs).

The true strength of your healing team comes from versatility in what they can do, not from getting the X people with the highest raw HPS potential.

Hmm, I grant there's a place for it, it just seems like it only really shines if you end up assigning multiple healers to tanks, which rather defeats the principle benefit of Beacon anyway. On our Heroic Anub kill, Flashing the raid with beacon on a tank would have just about countered swarm on the tank, while doing very little but give extra healing to Anub. Ofc, we let everyone except the tanks sit sub 1k HP and relied on excellent reflexes from cold healers. Possibly I'm just an unreconstructed dinosaur, but the merits of Flash just never appealed to me.

What the? No - you heal both tanks via beacon/FoL on Heroic Anub. The fact you are using a block tank means a lot of small hits, and the haste buffs implies frequent hits. Any massive healing you do with HL simply gets converted back to Anub HP. If you use two add tanks, then just diversify appropriately given that the add tank damage will be even less due to the frenzy mechanics.

If you are not using a single block tank add-strategy, then just use whatever makes sense for what you are doing. Perhaps you are confused by the nomenclature of "one tank" Anub strat, since it implies one tank for only adds. You still have a dedicated tank on Anub.

I'm in no way confused by the terminology, it was simply absent from your first post (which actually alluded to multiple block tanks anyway). We use dual add tanks for no other reason than that interrupting Shadow Strike reliably was problematic when they were stacked. Holy Light spam essentially allows the MT and one of the add tanks to be hotted and forgotten about by the other healers, who can then devote their full attention to Penetrating Cold, which is the principal danger if you have any hope in hell of beating the enrage.

I'll answer my part:
first off, tank damage IS predictable. Maybe we had a confusion of terms?
There are phases and special boss abilities (mimiron: plasma blast, Twin Valkyrs:when one in shield, the dtps increase for the other tank). There's the fluctuation in the incoming damage, which is not the same as being unpredictable. I think these fluctuations are referred to as "spikes". If you have a predictable and stable stream of healing, the fluctuations will have a minimum effect. A constant 7k HPS on tank with 6k-10k FoL heals every single second that your healadin is standing still and casting can as well be better than a 5k to 20k healing casts every 1.35 - 1.40 seconds depending on a hit/crit or under the effect of DP (which is again minimal with FoL since mp5 shines with that build)