Ok, this is annoying. Her burst is almost unmatched among other mages. It's like Anivia but mana efficient, more durable, and not a base 310 movement. Once she has has her 3 spells if you can land the root you can almost guarantee they get pushed out of lane, if not killed.
Not to mention her MP5 is disgustingly high despite her relatively low mana costs. Why not give lux this kind of MP5 when she ooms herself in 2, 3 chain casts if she doesn't have an Archangel's.
The design to her play style is fun, but in definite need of fine tuning.