This thread is a bit late as the tier is almost over, but hey, better late then never.
First we must take a look at each talent.
70% move speed for 8 seconds every 45 seconds
45% move speed for 3 seconds when you use judgement.
15% move speed + 5% for each holy power up to 3 resulting in a max of 30% move speed.
Speed of Light is actually one of the strongest ones of these in actual fights, however it is not as easily comparable as the others, so lets compare PoJ and LAotL first, returning to Speed of Light for the fight to fight discussion.
Now, what we must remember for LAotL is that it scales very well with haste and SW (tier5), which I personally think is the best choice for tier5 talents on most fights. Some exceptions where HA/DP can be better, but that is another discussion.
Looking back at some logs for me, I seem to be between 65-70% uptime. Now just looking at this. LAotL gives more average movement speed than PoJ for me, so really, I could just aswell remove PoJ from the discussion right here. Though, I am going to stomp it a bit more before doing so.
LAotL also works very well for gap closing whenever you for some reason need to swap target or generally just reach a target that is not near you.
The fact that PoJ that is known for good "static" movement speed gives less average movement speed than LaoTL at decent haste levels, and hey, a buff with 70% uptime is not really unpredictable. 70% uptime on LAotL = 31.5% move speed average, whilst PoJ at 3+ hp is only 30%, and you won't have 30% at all times. Now, when you have AW activated with SW talented, you get 100% uptime for 33~ seconds. It has happened for me that I have used AW as a movement speed increaser for when I needed to kite for longer periods of time, like 15-20 seconds. Having 45% move speed for 33 seconds is very good actually. Not very often you have to kite for longer than 30 seconds, and even if you did, you still get more move speed from LAotL anyway so, even in a fight where say you had to kite alot, LAotL would still outperform PoJ, with the added benefit that you can use SW for a long time speed increase.
Now, this is the important part. Obviously, movement speed is only relevant when you actually have to move. Alot of tank movements are short, usually just run from 1 place to another and usually takes less than 3 seconds. Which makes it so that most times that you actually have to move, your LaoTL gets 100% relevant uptime, as it is up for the entire movement.
So really, in most situations, LAotL is simply a flat 45% increase in speed since it often have 100% relevant uptime. And lets say you sit at 4.5s Judgement with haste. And you got a longer movement part. Lets say it lasts 6 seconds.
During those 6 seconds you will still only have 1.5 second down time resulting in a 75% uptime. If it lasts 7 seconds you would still only have 1.5 second uptime resulting in a 78.5% effective uptime.
So really,
LAotL > PoJ in any short movement ( Huge difference )
LAotL > PoJ in any long movement, especially with the added utility of combining it with SW.
There are 2 occassion where PoJ is actually viable.
1. When you have no mobs to attack / out of range of every mob and you need to dodge abilities.
2. When you have to do alot of short movements over an extended period of time to dodge alot of dangerous abilities.
Lets give an example of this: Say a boss got a phase where he start shooting out a barrage of dodgeable AoEs that is very very bad to get hit by.
Then having the constant movement speed for PoJ so you don't risk getting hit by a spell during that downtime may be good for the feels.
Sadly, there are no examples of either of this in this tier. We will see in next tiers, but for now, these are not relevant except for 1 exception which I will take up later.
I have not talked so much about Speed of Light yet, that is simply because, it is not comparable to the other talents. It has very obvious use. Any fight where you got to move rarely it is good.
But lets go into fight to fight basis.
Mogu'Shan Vaults:
Stone Guards: Not so much movement on this fight, which talent is not really a huge deal. The fact that it is rarely movement on this fight makes Speed of Light attractive. Speed of Light can be used nicely to put up tiles on heroic mode and clearing the cobalt mines.
It all depends on how much movement you do in your group. I usually both clear mines, stack up some tiles and have to chase our other tank since he likes to run around, so I opt for LAotL here. Possible to use AW to clear mines and get tiles up.
Feng the Accursed: Same as before, not so much movement here. LAotL or Speed of Light here. Only movement really is the phase changes and killing the adds during the shadow phase. So Speed of Light is probably the optimal talent here with LAotL being behind it.
Gara'Jal: Only movement in this fight is in the shadow realm.
Normal: If you are only killing your spirit, go Speed of Light, it will help you reach it the fastest. If you help killing spirit as long as you can, go LaotL
Heroic: If your dps is helping you alot and you only need to kill 1 severer, go Speed of Light. In my group I have to kill 2 severers, sometimes even 3, which makes me opt for LaoTL.
Spirit Kings: This also depends a bit of your tactics. If you are using a tactic that involves kiting the bosses, speed of light could be useful. I use LaotL because we never kite the bosses. I feel it is just stronger for dodging the double warrior wall and for the rest of the minor movements in the fight. In the end, it does not really matter much.
Elegon: This is a fight where I just think LAotL shines. It works so perfectly with adds spawning, resetting stacks, etc. Basically, every time and add spawns you can LAotL to it to reach it fast. You can stay longer in elegon in the middle before going to pillars. After killing a spark you can reach Elegon faster. Basically, so many predictable small movements. Also great in the last phase for resetting the stacks. Great for kiting the small adds aswell. Speed of Light works good aswell however you can not have it up for every stack reset in the burn phase making me opt for LAotL, however speed of light is not bad at all.
Will of the Emperor: This is the only fight where I think PoJ is viable on in this tier. It can be nice during the combos. Combos are the only movement here really. LAotL and PoJ is really even here, depends a bit on your playstyle, either choice is fine. I used to use PoJ before but use LAotL now as I learned the combo better, it was just not an issue.
Heart of Fear:
Vizier: I think LAotL is very strong here for platform changing, dodging the orbs. Another thing I do is everytime the boss casts exhale I time it with a judgement so I can intercept the beam faster. Speed of Light is also very valid, good for platform switching however lacks in intercepting exhale and ring dodging. Its a matter of playstyle, both is fine.
Blade-Lord: Not so much movement here. LAotL wins out for boss "kiting" when you need to move the boss, however the major part is the last phase where I think Speed of Light wins out, so I would chose Speed of Light for this fight. LAotL second.
Garalon: Really does not matter. If you are kiting LAotL or Speed of Light. Speed of Light allows you to take the pheromones faster however LAotL is better for the actual kiting.
Wind-Lord: Does not matter
Amber-Shaper: If you are the fling tank, LAoTL will allow you to reach the boss fastest again. Other than that, does not really matter.
Empress: LAotL works great for giving the ranged the poison debuff aswell as add kiting if needed. Speed of Light can also be used. Matter of playstyle.
Terrace of Endless Springs:
Protectors: LAotL is great during Elite Mode to move from the Expel Corruption. Movement does not really matter otherwise on this fight. LAotL wins imo.
Tsulong:: LAotL is extremely strong for positioning the boss when a new sunbeam spawns. LAotL wins imo.
Lei-Shi: LAotL is good for gap closing. If you are using a tactic with kiting the adds that spawns each 20%, Speed of Light can be good. Otherwise LAotL.
Sha of Fear: LAotL is the best for picking up orbs if you are on orb duty. It also works good when you come back to the platform. Speed of Light also viable.
Conclusion: Basically, on every fight, LAotL and Speed of Light is viable. On some fights one is obviously better, on others, they are pretty even and boils down to your playstyle and how you kill the boss. Movement is not really a huge deal this tier to be honest.