As a Taliyah main with level 7 mastery on her...
Please revert the Vector Casting change on her W. It's ridiculously clunky and fidgety now. I can't even simply knock the enemy up anymore. I'm forced to toss into a direction, which is something that also screws me up when I misclick and knock the opponent away. The only change that was needed is to let her cast other spells while casting W. It just feels like a complete mess now.
Also, I can't see the radius of it anymore, so that really messes with my aim.
EDIT: For those that doubt my experience with Taliyah, I have 78.5k Mastery Points with Taliyah. I mainly play her Support and occasionally Jungle. However, this isn't about Mastery Level and never was. It was to bring some validity to my point.
EDIT2: Please refer to these two topics for any other further discussions: