First and foremost, I'm an Aussie who plays on NA servers. My ping is about 250ms with a tunnel service, and 400ms+ without. For the most part I accept any latency I get due to my location and am used to it for anything else mechanic related in this game including end game fights aside from one thing -
Mudras.
Now I am not all that savvy with programming or networking to understand how server side / client side systems work, and whether or not this is even possible however-
Mudras are extremely latency dependent due to the short CD (0.5s). When watching videos of other ninjas playing in NA or even EU, I get rather jealous of how quick their mudras activate due to their ping alone. As a competitive player it puts me (and other english speaking countries that are across the globe) at a rather large handicap.
In addition to this, any ninja (whether you are in Montreal or Australia) that experiences gameplay during highly congested times (or when the server is struggling) can tell you of their experience with mudra rollback, and how infuriating it is when it happens.
I am perfectly fine with the decision to choose a server side structure for everything else in the game currently, however when mudra rollbacks start happening, it just makes ninja a very clunky, not-fun class to play.
You should bunny when you hit the wrong key combination, not when the server decides to reject your input due to packet loss or similar.