The level 15 talents focus on movement, akin to the “charge” tiers of warriors and druids. Most high end brewmasters take Tiger’s Lust, though at the beginning of the expansion that was the least popular talent due to a chi cost. However, Celerity and Momentum aren’t bad choices, either.
Celerity:
Favored when there is an abundance of ground fire to be rolled out of.
Tiger’s Lust:
Favored because of the short cooldown and instant sprint. As much as we love Roll, sometimes being able to control just how far and fast you go is useful. Additional utility in that this spell is castable on others, and it’s better at carrying you across long distances than roll. Overall, this ability was pretty overpowered, and only got dragged down because it was a usable skill instead of passive (meaning you have to remember to use it).
Momentum:
Sort of a mixture between the two: No extra button, but gives you a moderate speed boost. Really nice for leveling.
After the removal of the chi cost early in MoP, Tiger’s Lust became the top choice for raiders. However, it wasn’t a vital choice most of the time. If you wanted, you could happily choose Momentum or Celerity.
Is that an effective tier, when one choice is superior, but is rarely crucial? As long as not all talent tiers are like that, I think it’s passable, and better than the alternative of having two completely useless talents complete with one awesome talent. However, I would rather have a tier that was changed regularly depending on the fight.
In the future, as much as it pains me to say this, I think this talent tier would benefit from the loss of Tiger’s Lust. Roll is our signature monk ability and the whole tier should be devoted to its use; it should not offer an ability that is better in almost all ways. We already lost Clash because its overlapping utility with Roll, and I think most people would agree with me when I say that Clash is far more interesting and unique than Tiger’s Lust. Actually, if I could I’d like to replace Tiger’s Lust with Clash or something similar, since it’s more unique to monks than a basic sprint. Thinking purely of the movement aspect of Clash, that could be situationally useful while not always being the first choice. However, I can’t see many applications for healers whereas Tiger’s Lust is nice for all three specs.
I like Celerity as is. It increases the usages of our signature ability in a clearly useful way.
Momentum is a good idea, though I think the 25% boost is not strong enough. Sure, it can stack up to 50%, but only if you use both roll charges. That’s not something I’d like to encourage. And Tiger’s Lust is still faster at 70% instantly. I think the intent is to act as a long duration (relatively), small speed boost; almost a passive speed boost. While that comes in handy while leveling, where one might roll every 15 seconds, you won’t find that same regularity within a raid environment. To improve it, I’d like to see a bigger speed boost, maybe without the stacking to keep the speed reasonable. Something like a 70% speed boost for 4 seconds would be useful and competitive.
Thinking about how the three of these are used… Roll by itself excels at speedy, short distance movement. Fire appears under you, roll out. Branching off from this, Celerity lets you do that speedy short distance movement more often. Fire appears under you regularly, roll out more often. Momentum attaches a speed boost, useful for longer distances and more regular but minor movement speed. Then we have Tiger’s Lust, which is excellent for precise, long distance movement.
Overall, this tier is unlikely to see any change because it’s good enough, and this whole post is overanalyzing everything.